The problem I found with Frog Toggs is that they get noisy when you move. I haven't checked the newer models though. Does this seem like it might still be a problem?
I have an old Mossy Oak branded cheap ($100) rain suit that works great and is very light weight, but I would never wear it anywhere but up in the tree or on a boat. I think thorns would shred it.
I really like the current US Military rain gear if you can find a pair and they seem really tough.
Silicone spray...CampDri. (SP) I spray all over my boots and works pretty well I prefer 2-3 coats myself. Also put on clothes to help but, don't think it will repel water if you fall in a river but should do well with a light rain.
I found Kiwi Camp Dry spray that is sold in most stores. Is that the stuff?
LOL! Yeah, I don't plan on going swimming, just don't like the rain.