When I asked the question about my Gore-tex Stohlquist, this is the advice I got:
Count, wash it using nikwak tech wash or whatever stohlquist dictates. rinse extremely well, let it dry(no dryer) and then retreat the dwr, let it dry(no dryer), then iron it on a low setting avoiding the gaskets. should be good as new.
the dwr i used was revivex...worked great
"The world would be a better place if everyone kayaked."-Brad Ludden (Valhalla)
"You only get one chance to run a drop blind."-DD
More than likely your dry top is still waterproof but your DRW has worn off.
The DWR(Durable Water Repellency) is generally a sprayed on teflon coating of sorts that prevents water from soaking into the nylon fabric. Once this wears off which it does after time the nylon will hold water and wet out, making th inside of your top damp feeling.
As count pointed out ironing your top works great because it heats up that coating and brings it back to the surface.
Count's directions are spot on.
As far as your actuall waterproofing, yes it is possible for your waterproofing to wear off if you have a PU coated piece that is 2 layers. If that is the case I am not sure about how well those treatments will work I doubt it that they will.
where can i buy this stuff, i assume at kayak shops, but if there isn't one around do they sell this stuff anywhere else, hardware store maybe.
and i have plenty of chest hair, im thinking of making a rug