Cleaning Seatbelts and speaker grill cloth

[kustomsol]

What products have y`all found effective in cleaning seatbelts; mine are 13 years old. They did matched the brown leather/vinyl/carpet in the car, but now are a very dingy brown. I`ve read the threads on cleaning them using "not too much water" and be careful with some things that could weaken them. Are their any commercially available spray or foam cleaners which work and are not going to weaken, melt, unravel, etc. the belts.



Ditto for speaker grill cloth.



Thanks