I have a jacket made from "Sympatex" fabric which was in need of washing and reproofing. As it was rather expensive I wanted to do it correctly so I e-mailed the manufacturer who recommended this product.
The product is very simple to use. There are two bottles containing 300ml each of wash and reproofer. You add up to 150ml of Tech Wash according to your water hardness and this will do one or two garments at a time After the wash cycle has finished you add 100ml per garment of the Wash-In which is the reproofer ("...reactivate the hydrophobising" as the manufacturer puts it.) and run a 30C Synthetic cycle with a slow spin. You can wash and reproof up to two garments at a time.
The items can then be air dried or tumble dried if the care label permits.
It is also possible to hand wash garments if preferred.
The results were excellent, the jacket actually felt lighter, (it can't have been that dirty!) and its water repellant properties were restored to as new.
I could have had it dry-cleaned and reproofed by a specialist but it would have been more hassle and probably more expensive.
As well as "Sympatex" fabric the products are said to be suitable for "Gore-Tex","Permatex","eVent" and "Nikwax Anology" fabrics. The Tech wash is also said to be suitable for items such as tents, awnings rucksacks panniers and camera bags.