I'd like to know this too, my budgie won't eat her pellets but I don't want them to go to waste.
I soaked them overnight in a full cup of water till they expanded 4 times there original size and mushy and then I fed them to my snails a few days ago, they ate it all up and are still if perfect health so they didn't have any digestion issues because they were pooping like normal. So it seems safe to feed once soaked, I guess I found a use for my birds uneaten pellets
Owner of 50 snails. White Italian and helix aspersa