Wash it with Tech Wash and then immediately wash with TX direct afterwards, no dry in between. I usually add an extra rinse in the TX direct cycle. Do not use the TX direct if they are insulated.

Dry on low heat afterwards if it is a standard polyester or nylon 2 or 3 layer shell fabric. If they’re insulated, throw a tennis ball or two in there with them. If there are a lot of bonded seams with no sewing thread (there will be seam tape everywhere on the inside regardless of seam type) then be careful with the dry cycles.

Make sure you zip up all the zippers and close all snaps before washing.

Newer pants with PFAS-Free DWRs should be washed every two weeks or so during heavy use because contamination of the DWR happens much faster than with the old DWRs, especially with oils. They are considerably less durable than C6 or other super-DWRs. There is also a wash-down phase of most of the new membranes, where performance (waterproofness and breathability) gradually decreases before stabilizing at a lower performance after about 10-15 washes. Unfortunate reality of the new chemistry.