I am wondering about the best products for

(1) heel inserts (I have a pair of pumps that slip and give me blisters)

and

(2) leather (not suede) weatherproofing for boots. I used to get at the cobbler's this silicone liquid that came in a bottle with an cotton-ball-on-a-stick-type applicator; I liked that stuff, but now I can't find it anymore, and I'm out. I think the brand name was Kiwi. I have looked but don't see it online. What do you use?

Thanks!