It is specifically designed to work with Goretex fabrics and DWR coatings. It is scent free and does a great job of getting the grime out. It is meant to be used in combination with their TX Direct treatment, which re-ups the DWR coating. Techwash is the soap, TX Direct is the water repellent. Follow the directions carefully and these products work well and as advertised.
I haven't used this stuff on KUIU specifically, but a dozen other brands including Sitka, Patagonia, Arcteryx, etc. KUIU recommends Nikwax products on their web site, for what it is worth: http://hunt.kuiu.com/?p=503
None of them have uv brighteners. Apply whatever DWR restorer you like. I use TX direct for hunting clothes as it has no order but use 303 protectant on my ski gear as it gives better results. Nothing is good as factory applied DWR. Most are heat activated so either dry the garment on med high or if instructed not to you can iron them after application. It also doesn’t matter the clothing maker, they all pretty much use the same DWR coating.
I have used it on my attack pants. Also have used it on my ski gear for 17 years. The tech wash gets stuff clean. Then use the TX-Direct Water in the spray bottle for DWR Treated soft shell stuff. Spray it on while the garment is still damp from washing it.
I use the wash it in TX-Direct for my ski gear, but I prefer the spray bottle and a topical application for my soft shell hunting fabrics. Let it dry and hang in the garage for a couple days. The water proofer makes garments smell at first, but the other goes away after hang drying for a few days.
I have used Nick Wax products on hard shell fabrics, soft shell fabrics, gloves, smooth leather, and nubuck boots. Their products work and are worth the investment.