In reply to Gordonbp:
If you machine wash quick cycle cold or 30, with Tech Wash (and no other detergent or conditioners) and use either down proof, polar proof or TX Direct (actually I'm not sure they are vastly different) in the fabric softener part of the wash depending what you are washing them it "works" without tumble drying. If you don't need to wash again making up solution of the relevant water repellent in a bucket with slightly warm water and spending time to kneed the item in the water, you can watch the water slowly go clear as the garment picks it up and this takes a bit of time 5 or 10 minutes of doing that. Wear rubber gloves. Hang to dry.
Once air dried, tumble drying (if garment ok) for a short while helps because it fluffs the fibres on the surface which helps the water repellent work. So it's helpful but not essential.
In my experience re-treating stuff is never as good as new, but definitely better than not doing it.
I did this with 2 pairs of over trousers, 1 jacket, 1 fleece and a fibre pile (remember those?) in the last week.
Post edited at 16:34