I cleaned our portlights on our 44 with a product called prism, https://www.amazon.com/s/?ie=UTF8&keywords=prism+cleaner&tag=googhydr-20&index=aps&hvadid=177606952444&hvpos=1o1&hvnetw=g&hvrand=8701734096420105074&hvpone=&hvptwo=&hvqmt=b&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032827&hvtargid=kwd-59633162726&ref=pd_sl_5eekfm3a5p_b. Can get it other places, but did an excellent job, you can use on stainless also. A little goes a long way.
