Is something used to make cards slid better for the bottom deal ?
Sometimes it befalls me that some cards of the deck are too humid and so they comes out together from the deck during the esecution of the bottom deal
I've never tried using anything on my deck, but something like fanning powder sounds like what you want. It's used predominantly for making a deck fan better (the clue's in the name ) but I expect it would help for this as well, as I think it generally just stops cards sticking together. Might want to wait for someone else to confirm that though.
Try to use another deck with different finish, and I don't reccoment you to use any kind of "super powders". You must rely only on the deck quality and your skills, not on ability of using some sort of additional helping.