I’ve been wiping down the foam with a damp cloth when I start getting really sweaty, at which point my glasses fog up anyway. Then I let it air dry, cool my face down (takes about half an hour), and go again. I got a silicone cover which keeps the foam clean, but it just causes my glasses to fog up extra quickly so I gave up on it. Instead I ordered some cotton covers from vrcover (still waiting for them to arrive) which should be a happy medium.
Daily cardio work in VR has definitely made a difference to me. I’ve been back at the gym for the last few months doing mostly weights - feeling much better than I did in 2020 - but when it’s been too wet outside to go running or biking, VR has been a good substitute.