Coarse, Rough
If you find some rice in a top hat it's going to be really coarse and rough. Probably because it's not the kind that's meant to be eaten.
Imagine trying to eat the rice you found in a top hat. It's so coarse it feels like it's scratching your teeth. There's probably some dirt in here too. This wasn't the best idea.
そ
あら
None
You take the coarse rice and try to wash it with soap (そ).
If you were trying to make this coarse rice taste like soap, you did it. But if you were trying to make it less coarse, well... sorry, but that's not how anything works.