Before getting into the main body of my answer, it should be noted that according to the company's guidelines a water-repellent product (DWR) should be reapplied "about every 5th washing cycle."
Refreshing the Durable Water Repellency (DWR)
The DWR of water-repellent products can be re-energized after washing by giving them a heat treatment.
To this end, tumble-dry your product for approx. 5 minutes or iron it carefully. When ironing a product, lay a cloth between the iron and the garment.
With this refreshment of the DWR, it is sufficient to re-impregnate your product only about every 5th washing cycle.
Here are some tips that might be of help to you in getting rid of those unpleasant smells in outdoor clothes.
"Odor in workout clothing is most commonly caused by a buildup of sweat and bacteria from your body."
"How you store your workout clothes can also lead to additional odors—for example, leaving sweaty clothes in a closed up gym bag, locker, or hamper."
Some general tips:
Turn clothes inside out before washing (since the sweat, oils, and bacteria from your body accumulate on the inside of the clothes). (Mammut recommends this step also)
"Always use the sniff test before putting the garment into the dryer," Zeitler says. (You don't want to "cook" the smells in.) Mammut recommends "tumble-dry your product for approx. 5 minutes or iron it carefully."
Wash clothes as soon as possible after wearing.
If possible, let sweaty clothes air out immediately rather than stuffing them into a plastic bag or hamper.
Don't use more detergent than recommended or overstuff the machine, both of which make it harder for clothes to rinse clean. (In my tests, every single method did worse if I crammed too many items into one load.) - The Absolute Best Way to Get the Stink Out of Workout Clothes
What does Mammut washing instructions tell us:
Always read the care label before washing your clothes!
Close all zips and velcro fasteners and then turn the garment inside out.
Wash with liquid detergent and rinse thoroughly.(Do not use washing powder since this blocks the pores of the membrane).
Leave the garment to dry completely.
All said and done Mummut says you should not washing powders or fabric softeners. It seems to me you could try this product: Nathan Sport-Wash.
Before using any new product on clothes please read the particular labels to see if the ingredients of this detergent are safe to use. If in doubt, one could email the manufacturer at Mammut.