i really do not know how the silicon would work. I do think your reasoning why it would work kinda makes sence but what about the smell of the silicon.
the cheap version of a sent loc suit is a military chemical warfare suit. go to the military surpluss store and inquire about one they did not use to be expensive but who knows with all the terrist crap going on these days.
this suit will leave black on you so make sure you wear something under it. the suit will keep you very warm.
hope this helps out