I have put small brushes that I have used for epoxying in vinegar and they cleaned up nicely.

: You can put a brush with epoxy on it in the freezer and stop the setting up
: action but remember, if you have a working time of 30 minutes and you have
: you have used the epoxy that's on your brush for 15 minutes then you only
: have 15 minutes left before the old epoxy on the brush sets. Perhaps in
: the middle of brushing on your new coat. If it's a good brush I would go
: for the cleaning. Giggle it in a cup of alcohol and wipe it off with a
: rag, repeating this several time. The easiest way is to use cheap
: throw-a-way foam brushes and perhaps put them in the freezer one time if
: you haven't used it too long. The same with foam rollers.

: John