Interest: general mountaineering/ hiking/ backpacking/ skiing/ kayaking
I usually wash my soft shell jackets & pants as least as possible, maybe two or three times a year. About once a year I soak them in a Nikwax product to restore the repellency.
A few yearsago I got hemlock sap on a jacket. I used butter to soften the sap and rubbed a bit of detergent on the stain when I washed it. The sap was removed, but the fabric is a bit lighter in colour where the sap was.
Butter, cooking oil or peanut butter is probably the least invasive way to soften sap.