In reply to buffalo606:
For technical wash products you're best placed going with Nikwax.
The Mountain Hardwear B'layman is a synthetic jacket as far as I'm aware which means it can be washed with regular tech-wash (although check the label to make sure) as can the trousers.
Once they're washed give them a shake off and spray thoroughly with TX-Direct Spray to improve beading and breathability.
Now comes the magic - give them a short blast in the tumble dryer on a very low temperature (30 degrees or less) to set in the proofing agent in properly - be sure to keep the temperature low or you risk permanently damaging your kit. No need for tennis balls either when washing a synthetic jacket.
Doing the above will help get your kit clean but maintain the water resistance to previous levels.
You can find Nikwax Tech-Wash and TX-Direct spray here:
https://www.alpinetrek.co.uk/nikwax-tech-wash-tx-direct-spray/
Hope this helps!