I did one with Nikwax wash and reproof and it was a complete waste of time - had to have it professionally reproofed to make it usable again. I did exactly what it said on the tin but the products didn't.
l got some of nikwax which did the trick...just put it in the washing machine with the rug [nothing else] worked out fine, but as most of mine are rambos, rhinos or the light weight amegos l just wash them in warm water...provided l don't use soap they stay waterproof..just did a couple of spares
if the rugs are too big or too heavy l have to send them away as l can not get them to dry very well
a friend go's to the local laundry [in the evening] and uses there machines and dryers
When I used to wash/proof rugs (for other folk) - I used Fabseal Gold (think that was what it was called) - bought it in a huge tin (friend who did rug repairs got it for me) - you brush/spray it on - it was very good!
I've found that the wash in proofers are a waste of time! But what really ruins rugs(the proofing) is putting them through a tumble drier!!!
Dont shoot me!!!! I use Thompsons Waterseal by ronson. Either one coat of the gold or 2 of the normal. It's a watersealant for bricks and I guess bricks need to breathe. Been using it for a few years(started with the dodgy rug from ebay that wasnt waterproof)quite successfully. In fact the first time I put the rug on the wall and slapped it on with a paintbrush only to find my technique had splashed lots of it into the fish pond - the fish are still living!!! Its a bit stinky so I leave the rug airing on a gate for a few weeks until smell has gone.