In reply to VS4b:
Wash in non-bio detergent at 40 degrees to remove old grease and oil, then wash in Nikwax Techwash on a quick cycle to remove detergents, then another quick wash with Nikwax TX Direct. Check all this corresponds with the washing instructions on the individual jacket and it should be back to like new. If you can tumble dry it on a low heat this may help to re-activate some of the original DWR