I need to use the self clean on my Rowenta professional iron
On the Rowenta DX8750 Professional model you fill the water tank, set on high, and HOLD the steam level lever all the way over to the right (where it says "self clean"). I did not see the info on the internet anywhere (not even in an online manual I found - my husband pointed it out to me.
You have to hold the lever over the entire time, it won't stay in that position so you almost have to use two hands. Pick the iron up hold it as you would ironing and rock it back and forth bottom to top. It's good to have a cloth under the iron so the yucky stuff doesn't get on your ironing board. I rocked it, and then would lift it nearly vertical and flakes of yuck would come out in the steam, and browinish yucky stuff would come out of the steam holes - just clean that off the sole plate when cool.