Yuki, that stuff works best in a front-load machine.
Larson, the Gore-Tex isn't gone, it was always laminated to the inside of your jacket. Its the Durable Water Repellant (DWR) finish that makes the outer fabric water proof. Anyway, easy to restore with Nixwax or Grangers. You might want to read this FAQ on Granger's site.
To save anyone the .... of "Idiot in The Laundry" department, I'll confess to wandering around for a few days wondering how to follow the directions ...
"Wash garment using a non-detergent laundry product prior to application" :
Finally bit the bullet and asked wifey just what the hell is a non-detergent wash product. She said to use the Ivory Snow flakes and we had a ton of the the stuff.
Then I loaded up the machine and dumped the flakes on top and let it rip. :
An hour later, I open the machine to find all of these "cottage cheese" clumps on everything.
Ok ... so I should read "Hints from Heloise" more ... but ... whatcha' do is add the flakes to the water gently and kind of swish them around to dissolve the flakes before you stuff in the jacket and pants.
About the only advantage to a machine is that at least the stuff is gettng full exposure to the product by getting swished around. With an insulated jacket half of the battle was getting the damned jacket to sink cause of all of the air trapped. What I do now is to roll the thing up like a tight sleeping bag to get the air out when it's dry and then stuff it in while it's still tight in order to sink it.
The first time I did this .. glad the kids were in bed cause Daddy was soaked to the armpits trying to squeez the freakin air out and my Navy vocabulary was in high gear.
Between the "cottage cheese" & sink the jacket ... :
They tell you not to use a detergent because it tends to leave a residue that keeps water from beading up (that's how detergents work - breaking surface tension), thus defeating your goal of water repellancy. If your DWR seems to be gone after only one or two washes, this might be the real problem.
If, however, detergent's all you have available and you want to avoid a shopping trip, just run the machine again without adding any detergent.