Isn't the paper glossy? I don't soak it and everything has been fine so far. I haven't tried manuals yet but NES and Gameboy boxes are fine. Value Village likes to put price stickers directly on those, same with book dust jackets for some stupid reason($79.99 in the display case with a the price stickered on it

).
I did use some damp paper towels to clean some dirty Genesis manuals awhile back, every page was covered in dirt. Nothing ruined when I was done with them.
I've heard of people using lighter fluid successfully, I just don't want to buy some as I don't need it for anything else.