Here is the rice cooker I own:
There is a removable pan which is Teflon coated.
A few days ago, cooking 2 cups of rice I thought it was too slow so I put it on direct heat (oven) to make it faster. After 5 or so minutes, the rice was slightly burnt. I tried (hot water + dish washing liquid) and (lukewarm water + washing powder), let it rest for 24 hours but to no avail. I don't know how to properly clean the burnt residual from the Teflon pan.