DO NOT use Draino or any other drain clog removal chemicals to clean a washer. It could damage the tub seal, drain lines and/or pump & impeller. If you wish to clean the washer, you need to access the drain pump and remove the drain lines and flush them out. The following link explains how you can access and remove the pump:
I would recommend you UNPLUG the washer and take it to a location where you can flush water through it. Preferrably outside, or in a garage. If you lie the drain hose on the floor and fill the wash tub with a garden hose, simple gravity will flush water through the tub basin, drain pump and drain lines.
If you have any questions about these procedures, please post back and let me know. I hope you find this information helpful.
NOTE: The drain pump has only one moving part (the impeller). It is a common place for debris to collect. Remove the two drain hoses on the pump to inspect.