For a wash, Woolite works fine, as does a mild/diluted laundry detergent, a car wash brush and a good rinse. I've used Raggtopp protectant with good results. There are others too. Most are a form of water repellent with UV block.
fluoroacrylate copolymer is one possible water repellent in Raggtopp. It's used in the textile industry for exactly this.
Tinuvin is also a likely UV block. Also commonly used on fabrics to prevent fading in the sun.
My experience with Raggtopp is that it works and lasts months. It will discolor a lighter fabric top, especially if it is one that has a pattern look, (grain) such as Stayfast fabric. As it softens/blurs that grainy, high end look. I generally don't care.
I dispute the idea that Raggtopp makes a top last significantly longer. I seem to get the same amount of time out of the top regardless of 'product' use, about 5-7 years here in Jupiter. What really works to keep a convertible top healthy is a good garage. And I think, to leave up when not driving. If it stays folded (I like the top down all the time), the creases will take a set and fail faster IMHO, and that's where mine always fail.
Note: I've owned convertible sports cars since I was 15. It is what I like.