Water based products will moisturize vinyl as much as it can be, to my knowledge. Silicone is just not good for vinyl/rubber/seals and so on. I know alot like CD-2, but I get alot of 'don't use that stuff with silicone on those parts because of how it breaks apart with time and heat/sun'.
Not sure who to believe on that argument. They say use waterbased products on it instead,.. and there are a fair amount out now, in comparison.