The absolute best product I have ever used is called Raggtop, and is made by the Haartz company in Germany, who makes the convertible top material.
Their cleaner, followed by their spray conditioner/protectant, always gives me a beautifully clean, conditioned, nicer color top, that beads water like crazy.
Just follow directions, get it absolutely dry before you apply the conditioner/protectant spray, and prepare to be very, very, happy !
Another trick I like to do to tops if they are not worn out or loosed threading, is to wash, rinse, and extract all the water out really good, so you are removing even more embedded gunk, lint, etc., and really leaving a nice, pristine, canvas to condition and protect with the next step.
Dan F