I can not fathom the rubbing alchol not working.
I treated 3 pairs of jeans with it just this last weekend. Poistion bottle over sap, turn bottle over, let it soak into fabric, remove bottle, scrap a bit with fingernail and it's basically gone. Repeat as necessary.
But to take old sap that had been thru washer & dryer twice, took me no more than 3 minutes in total to remove.
Sorry to hear that it's not working for you thou