The evap can is just that an evaporator. When things evaporate lots of residue gets left behind. Right now the crack is your biggest worry, first you have to get that fixed. If you can do that successfully and the inner chambers remain intact I have actually has luck using mild soap and water solution to flush the canister. Once flushed you have to let it bake in the hot sun for a few days to completely dry out.
Just Got it, Give me time!