I have been using two products I first ran across when restoring Jeep Wranglers. I use the MOPAR Soft Top Zipper Cleaner and Lube, PN. 5066440-AA, available on Amazon and from your local Jeep dealer for about $10. It comes in a dispenser bottle with a built in brush for cleaning the zipper teeth as well. It has worked well on the boat zippers as well as the Jeep tops.

I also use the Jeep Wrangler MOPAR Soft Glass Cleaner. I was amazed at how the windows in the IP dodger looked after using this stuff, it really removed a lot of imbedded dirt, and made small scratches and swirls vanish. PN 5012248AA, about $12 a bottle on Amazon or at the dealer here.

Disclaimer, I don't work for Jeep or Chrysler, have nothing to gain if you try these products, the usual stuff.