Need to give our Rab outdoor jackets a wash - what's the preferred substance to use or is it all much of a muchness?
I'd go Nikwax. They've historically been far more eco-conscious than Grangers and worth supporting for that reason alone. My experience is that there's no obvious difference in performance.
Are you washing it to re-apply DWR it or just washing it to clean it? Pretty sure non-scented soap flakes are the way to go and a fair bit cheaper than branded "tech" washes.
And make sure the washing machine has had a cleaning cycle or hot wash with no cleaning products before you do the GoreTex / similar fabric.
Otherwise the washing powder / fabric conditioner residue can cause problems.
I've always used Nikwax and it works for me, until the jacket coating completely fails. Plus one for soap flakes (as well as tech wash), &Â pre a hot washing of the machine