I use the thin memory foam vive gaskets. They sop up sweat pretty damn well. I also will wear a sweat band on my forehead/eyebrows since I have thick ass eyebrows that collect a bunch of sweat. As for the gaskets, I have many of them...maybe 8-10? I just swap them out periodically (once they get sorta nasty). Then once I have no more clean ones left, I just wash them by hand in some lightly soapy water and rinse them with clean water. Then I just let them dry maybe over night and repeat!

Edit: These are the ones I get but it seems like there are cheaper ones available if ya look about.

If you're going to be sweating in a Vive, you need to get rid of the stock face pad and get these instead. They're slimmer, they don't soak up sweat like a sponge and you can easily wipe them down whenever you take a break.