Wow, that's what I call hardcore! Did you get the sap from the actual pine? That's kewl!

I have never had much luck with aspirin. It absolutely stinks, boils too quickly, burns into a messy black mass and still does not wet the surfaces. It might be because for normal soldering I just use rosin and have resorted to aspirin only to try to solder things where rosin does not help, like aluminium. I've read that aspirin is supposed to help, but it did not in my case.

A drop of hydrochloric acid was supposed to work too, but I have not tried that. Not that I am too keen to breathe hydrochloric acid fumes