I use lemon scented Pledge on the outside of my Shoei visor. I have a pinlok on the inside and I learned my lesson early on to never get any cleaner or polish even close to it or you'll screw it up.
I've used it on many face shields (and windshields) and the outside of my helmets for many years and I've never had an issue. It cleans well and makes it so most bugs won't stick to it. Plus it smells nice!
I got the tip from an adventure forum when I used to ride a V-Strom.