He says.
https://www.youtube.com/watch?v=dRXkt6Dgi4k
The secret is a product I have actually heard of and heard very good things about. Never thought about using it on a belt.
https://www.goldeagle.com/product/303-a ... protectant
I don't plan on using this because EPDM belts already last like 150k+ anyway. But what I should do is buy some of that stuff and treat my vehicles (interior mainly).