Don't treat your waterproof gear to anything less than the best. Nikwax Tech Wash® has been independently proven to be the best performing product for cleaning waterproof gear in a washing machine. It is the only product demonstrated to provide exceptional cleaning performance whilst maintaining 100% of the Durable Water Repellency (DWR). DWR is the waterproof coating waterproof jackets are supplied with when new.
In my personal experience of using Nikwax, Grangers and a couple other products, all of them get a bit of skin oils and grime out of Gore-Tex, and nothing more. Despite pretreating and getting specific instructions from Arc'terxy customer service, I have never managed to get rid of anything substantial (primarily black oil spots from bicycle chains or similar) with any of these Techwash products.
In my eyes they are all about equally useless (except for very basic maintenance).
Have you considered that these waterproof fabrics and their DWRs are not designed to have machine oil on them? I have never had Tech Wash not wash all kinds of mud and grime from mountaineering off my waterproof gear. I would imagine that if the detergents specifically designed to not strip the DWR off your gear cannot remove your stain, the ones that can will strip a lot more than the stain.
> Have you considered that these waterproof fabrics and their DWRs are not designed to have machine oil on them?
I have indeed considered that, and come to the conclusion that, in fact, no kind of clothing was designed with the express purpose of having machine oil on it ;) But life happens, and bicycle chains of oil on them, and waterproof gear is used in more scenarios than just mountaineering. I am not going to leave a €550 Gore-Tex jacket hanging in the closet 90% of days because it is only intended for mountaineering, and life in the city could get it dirty.
I am also aware that stronger detergents would damage the fabric. I'm not accusing the makers of tech washes of deliberately selling bad products or being too incompetent to find the secret formula that gets all waterproof gear sparkling clean without damaging it.
I am simply saying that the limitations of these products make them relatively useless to me personally. If they fulfil all your requirements, that's great and I am happy that you are happy.
Conventional laundry detergents won't shift bike chain oily muck, either. You'll struggle even with washing up liquid and a nail brush.
What I am saying is that it is probably impossible to shift such contaminants without damaging the DWR and/or the fabric itself, at least locally. That would not be a limitation of the cleaning products but of the fabric and the DWR.
I have long taken the view that outdoor clothing is to be used and abused, it needs to be functionally clean, not sparkling clean. If there is a stain on my waterproofs, or even if there is a big strip of repair tape, that does not matter as long as it does not compromise performance.
> I am not going to leave a €550 Gore-Tex jacket hanging in the closet 90% of days because it is only intended for mountaineering, and life in the city could get it dirty.
That's exactly what I do with my expensive technical outdoor kit - I only use it in the mountains.
The rest of the time it's stored carefully and not used for everyday activities. That's what I have cheap non-technical clothing for.
For the record, there's more than just oil that I have been unable to get out of my garments with technical detergents, and despite washing regularly my jacket also has brownish rims along the collar and end of the sleeves where the fabric rubs against the skin.
So I'll politely stick to my opinion that these special detergents do not perform as advertised.
My son used it for his motorbike gear, didn't do much with pureed bumble bee and the rest of the summers road grime, we'll see after the winter how it copes with salt-spray and the rest.
I'm more a pressure washer using car-wash detergent then re-proof with something that works (boot proofer) type.
I've always found the Dripak Liquid Soap Flakes cleans waterproofs and other outdoor gear just as well at Techwash, and it's much cheaper. I'd be interested to see the evidence that the Nikwax product works so much better.