Scrud! I have a build up of grey waxy substance on the outer casing of my kleenmaid front loading washing machine bowl.  have run the machine about 6 times using very hot water and washing soda on some runs, bicarb of soda and vinegar and now dishwashing detergent, but the scrud is still there. it has stained all my clothes grey :-(any other suggestions?

Take the inner spin bowl out & scrub it and the outer bowl clean of any soap scrud build up. Stop using softener if you use it as that and too much cold water washing is the main cause of the build up.

This sounds like what the service manual calls "scrud":
"If fabric softener is used regularly it will eventually cause a build up within the outer basket. This can result in black flakes present in the wash load that can stain garments. To remove scrud follow the procedure below.
Step1: Add a full cup of a good quality dishwashing powder in to the machine.
Step 2: Set the machine to a Heavy Duty cycle, select a Hot Wash temperature, High Water level and allow the machine to agitate for 10 minutes.
Step 3: Leaving the lid closed, turn the machine off and allow to soak overnight.
Step 4: The following day, turn the machine on and advance to the spin cycle to drain the water from the machine. After the water has drained, turn the machine off then back on again, and select a Heavy Duty cycle, Hot wash, High Water level, and allow the machine to complete a full cycle to ensure that all of the loose scrud and residual detergent has been flushed away.
Note: If there is an extremely heavy build up the above procedure may have to be repeated." (emphasis theirs) (http://www.applianceaid.com/pdf/517792A-PH7-USA-Eco-Washer-Service.pdf)

You said you cleaned the machine already, so maybe you did this step, but I thought it might help.

A lot of build up from front loaders is caused from "scrud" excess detergent or constant cold water use. Place a cup full of Epson Salts in the machine and run through a hot wash cycle every 4 weeks or so and this will help keep bowl clean.

2.13.1 Scrud
If fabric softener is used regularly it will eventually cause a build up within the outer bowl. This can
result in black flakes present in the wash load that can stain garments. To remove scrud follow the
procedure below.
Step1: Add a full cup of a good quality dishwashing powder such as Active or a similar product
into the machine.
Step 2: Set the machine to a Heavy Duty cycle, select a Hot Wash temperature, High Water level
and allow the machine to agitate for 10 minutes.
Step 3: Leaving the lid closed, turn the machine off and allow to soak overnight.
Step 4: The following day, turn the machine on and advance to the spin cycle to drain the water
from the machine. After the water has drained, turn the machine off then back on again, and select
a Heavy Duty cycle, Hot wash, High Water level, and allow the machine to complete a full cycle to
ensure that all of the loose scrud and residual detergent has been flushed away.
Note: If there is an extremely heavy build up the bowl will have to be removed for pressure washing

What you probably have is a build-up of scrud in the machine as a result of an interaction between the fabric softener and the detergent. This flakes off and marks the clothing.
Buy a commercially available cleaner for your machine for this purpose of do one or two cycles using a bottle of white vinegar in the tub without detergent. Clean the machine out doing another cycle using baking soda directly in the drum. Repeat this process if there are still any indications of scrud.
Take care that you use the correct amount of detergent in your machine according to load and water level and do a cleaning run about every 25 wash cycles to clear away any excess detergent that was not caught by the rinse.

What you probably have is a build-up of scrud in the machine as a result of an interaction between the fabric softener and the detergent. This flakes off and marks the clothing.
Buy a commercially available cleaner for your machine for this purpose of do one or two cycles using a bottle of white vinegar in the tub without detergent. Clean the machine out doing another cycle using baking soda directly in the drum. Repeat this process if there are still any indications of scrud.
Take care that you use the correct amount of detergent in your machine according to load and water level and do a cleaning run about every 25 wash cycles to clear away any excess detergent that was not caught by the rinse.

What you probably have is a build-up of scrud in the machine as a result of an interaction between the fabric softener and the detergent. This flakes off and marks the clothing.
Buy a commercially available cleaner for your machine for this purpose of do one or two cycles using a bottle of white vinegar in the tub without detergent. Clean the machine out doing another cycle using baking soda directly in the drum. Repeat this process if there are still any indications of scrud.
Take care that you use the correct amount of detergent in your machine according to load and water level and do a cleaning run about every 25 wash cycles to clear away any excess detergent that was not caught by the rinse.

What you probably have is a build-up of scrud in the machine as a result of an interaction between the fabric softener and the detergent. This flakes off and marks the clothing.
Buy a commercially available cleaner for your machine for this purpose of do one or two cycles using a bottle of white vinegar in the tub without detergent. Clean the machine out doing another cycle using baking soda directly in the drum. Repeat this process if there are still any indications of scrud.
Take care that you use the correct amount of detergent in your machine according to load and water level and do a cleaning run about every 25 wash cycles to clear away any excess detergent that was not caught by the rinse.

give a couple wases on full hot water and check little filters in hose line

There is no filter on this machine. The gray gooey substance is sludge (dirt) build up inside the tub. This can be caused from using too much detergent or a detergent that is not HE (high efficiency).
You can try running an empty cycle using the hottest water available with products such as "washer fresh", "affresh" or a cup of bleach to remove the build up.
Remember to use a HE detergent and you only need about 2 tablespoons per regular load.
Good luck!