nikwax - waterproofing

I'm not sure if this stuff works but I thought it might be worth a shot to make my madison jacket a bit more waterproof??

has anyone used this stuff before? I've go the techwash (currently in the washing machine) and I also have some tx direct.
Do I need to let it dry before giving it a second wash with the tx direct stuff or can I just sling it straight back on?

I'm not expecting miracles but if it helps a bit it has to be worth a shot

According to nikwax best applied when wet as it's water based

http://www.nikwax.com/en-gb/products/productdetail.php?productid=16&activityid=-1&itemid=-1&fabricid=-1