I have been using 'Fabsil' which I purchased from a camping shop a few years ago. Bought 2.5L of it and have done my riding kit, jackets / trousers etc. and my tent a couple of times.
No need to put this in your washing machine, you spray it straight on. I used a compressor and paint spray gun previously, but since it's not working currently, I used a pump sprayer the type used in greenhouses etc although any empty spray bottle will obviously do nicely.
A friend mentioned that he puts his stuff in the tumble drier when it has dried naturally. I have done this but can't say if it makes any difference.
It's a great product, the water just beads on top of your clothing and just rolls off. Think I may spray my bike in it!
It's not expensive for what it is and will last you ages. Just looked on Amazon and they have 5L @ £19.99 - Was £29.99 Bargain
http://www.amazon.co.uk/Grangers-Fabsil ... il+5+litre