Hi @og22 - Thanks for reaching out! If Nikwax Tech Wash and TX hasn't worked for you, we would suggest trying Granger's Clothing Wash and Repel. As you know, the instructions on how to apply the product are very important and you will find them in a video on that linked page.
You may also want to look at this Expert Advice article titled DWR Coating: Application, Cleaning & Care. There you will find lots of information on keeping your rainwear in good working shape and why newer rainwear usually needs to be cared for more often.
Let us know if you have any additional questions and we'll be happy to help!