I use black Plasti-dip as a primer on many things and they do make a clear version of it... Though I wouldn't use it on hands, feet or skins, I have been considering toying around with it on armor and masks, but haven't gotten around to trying it out yet. I think I'd still prefer Perma-wet for sealing skins, etc... but I am curious to see if the clear Plasti would work on armor in particular, as it is pretty flexible stuff and the armor doesn't have to be flexible like skin parts do. Definitely post up your results if you try it out.
for the sealing ive use many different things, i tried silicone spray, this works well but you need to repeat this many times. ive tried baby powder (or how you call it xD) this is a great method i used it on my spawn mask 4 months ago and its still looking great and flexible and its not shiny. i tried to use a mix of both but that diddent work well. i also tried an acrylic sealer but that broke of the rubber because its not flexible.