After wiping clean the inside of my visor with a microfiber cloth so many times the anti-fog that came pre-applied to the visor is beginning to wear off, and I'm trying to prep myself for something I can reapply on occasion. Last night I trialed a solution of roughly 9 parts 91% isopropanol and 1 part laundry detergent and tried it on my car's windshield. Do any of you guys have a solution/mix/blend/product/blend-of-products that you find is effective at keeping the inside of your visor from fogging up?