Nik wax products are generally excellent. Made for a more exacting market than golf. However Nikwash is just liquid soap. Breathable waterproof products have very specific cleaning requirements which you would be well advised to take heed of.

 As a general rule wash in soap only at no more then 40c (I use 30c in our machine). Cheapest product I have found is DP soap flakes.....dissolve 50g in hot water and use in detergent drawer in machine. On no account should you use fabric conditioner...I thoroughly wash the detergent drawer before cleaning any breathable fabrics.

 After the wash cycle repeat with Nikwax TX Direct wash in. This will, as mentioned, re-proof the fabric to restore beading. Then either tumble dry on low heat if the material permits or spin and drip dry.

 In the end there's no substitute for quality. Sunderland are the state of the art in my opinion. I still have a Sunderland suit which must be 15-20 years old and is still sound thanks to the routine I have described. I treat all my walking/fishing gear similarly.