Be sure to get a food grade one, and I don't see any reason they wouldn't work although you can get a big plastic conical for fairly cheap, they'll be much much easier to work with and won't require retrofitting
there are plastic hdpe liners you can get to fit them, I saw someone using them a long time ago. might be easier to just ferment in the bag, then just pull and dispose instead of trying to clean the barrel over and over again.