Two things I use for grease spots in clothes that might work:

first is any good hand cleaner, like Gojo, Joe's, or Permatex Fast
Orange. I've had best results with Joe's. Rub it in real good and drop
in the washer.

2nd is the hand cleaners sold in paint stores to remove paint, which
might be what you need to cut tree sap. Not sure how easy that stuff is
on clothing, so spot-check it first.
I suspect almost anything sold as a handcleaner won't stain clothes,
because inevitably a hand cleaner will wind up on sleeves occasionally.
- -
Rex Burkheimer
WM Automotive
Fort Worth TX

SteveB wrote:
How do you get pine sap out of clothes in the washing machine?