Very tricky! I'm wondering about lemon or orange peel (rind) - that's if you don't mind your bag smelling of lemon or orange!. As long as you put something in the bottom of the bag, like a bit of plastic or small dish so the oils from the peel don't get on your bag, that might do the trick. Or, I've heard that freshly ground coffee put in an old sock (put again I'd line bottom of bag!) is a good deodorizer - but your bag will probably smell of coffee! Better than seafood though! Good luck!