Just don't stick your fingers in your mouth when you're done and you will be fine. I don't think tetrodotoxin (the neurotoxin in pufferfish) has any effect if it isn't ingested, although you may want to do a little quick research on whether it can be dangerous if you get it in a cut or anything. I may be very wrong here, but I think it is the same type of toxin made by poison dart frogs, which can be deadly if you get it in a cut or break in the skin and it gets in your blood (thus the reason they are used to make poison darts). You can get some long gloves if you would feel safer that way, I've seen over the elbow gloves for aquarium maintenance sold online before. If the fish got chopped up and bits are in the water, I'd think a large water change would be the place to start anyway.
but I know there poisonous would it hurt me if I put my hand in there?
