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.
You can try pouring some grain alcohol in it and leaving it to soak for a couple of hours. After that, a normal scrubbing with dish soap should be enough. Use the cheapest vodka/ouzo/gin you can find.
The second option is vinegar, with the same usage.
You can add some vinegar and hot water, it should do the trick. You can leave it for around an hour, and the hot water is the important part. I clean pretty much everything in this way because it's natural and clean. If this doesn't work, try to boil the solution.
For really tough stuff in Teflon-lined frying- and sauce-pans I use sodium bicarbonate (baking soda) and bring the pan to a boil. Because of the higher temperature, you can supersaturate the solution by adding a lot of baking soda, making it very alkaline.
Because it looks like the vessel which contains the charred rice isn't supposed to be put on direct heat, you might want to boil water, add the baking soda, and let it sit.
I also use the cleaner SimpleGreen, which is an effective soak for many messes, especially burnt grease.
