try prochems flouroseal, thats what i use,
one good thing about it hardly any smell at all being water based, and theres no change in shade, in fact u could believe it is just water applying it, lol.
no idea how good it is really, i have been back to clean one carpet i applied it to, but not sure what carpet would hav cleaned like if i never applied it, need to test on same carpet, like for like.