Anybody ever let cereal sit in milk for a few hours then use it as a messy substance? Haven't tried it yet but I think I want to. It seems really gross but it's slightly arousing to maybe discover a different substance to play with.

That was one of my first messy substances as youth, though I used water instead of milk as milk has a tendency to smell. It's really quite good and makes a nice, thick slop. It doesn't cling that much, at least rice crispies don't, but you do get a good few bits clinging to you. It's not something to pour down the bath plug mind, but if you can deal with that it's fabulous.