1. DWR can be reapplied if necessary after cleaning, so don't worry about this aspect of the problem.
2. nail polish remover works, but this might do something bad to your fabric. [note: much older formulations contained acetone. not sure about present day formulations]
3. try cooking oil: pour some cooking oil in a cupped palm of one of your hands and rub it on the pine sap. work it in good. if it's still soft, it should come right off. see #8 below if it has already hardened. cooking oil, due to its relatively benign nature when compared to my other suggestions, would be my choice.
4. mineral spirits or paint thinner works great, but again, might damage the fabric. obviously, turpentine is a good solvent for pine sap (since it is basically made of the same stuff as pine sap). however, it too might damage the fabric.
5.commercial automotive bug, tar, and sap remover. this too might damage your fabric. if you use it on your car, you need to wash and wax it afterwards.
6. alcohol stove fuel (denatured alcohol) might work also. since this is a semi-polar compound, it shouldn't work as well as a non-polar solvent. while we're on the subject of fuels, you could also try kerosene - my guess is that it should work better than alcohol.
7. many years ago, heard that mayonaise might work. never tried it though.
8. if the sap has "set" and is hard, you might have to soak it in the solvent of choice, to soften it a bit.
9. if you use cooking oil, you'll need to wash it out afterwards. rinsing with water won't work (water is a polar solvent, and cooking oil is non-polar, hence it won't emulsify the oil and remove it). try hand washing and rinsing the spot/area only first to get the cooking oil out. DON'T use a detergent (dish, laundray, or otherwise) to accomplish this. use plain SOAP or one of the appropriate McNett ReviveX products - sold on this website. detergents will remove your DWR in a single washing as some who have posted previously in other Threads have testified.
hope this info helps. if you care to, let us know what you did and how it worked.