I understand soap molecules having polar and nonpolar ends, so that it can help nonpolar things dissolve in water. What I've never understood is, why doesn't soap clean off pine sap?
There are things that are much better at cleaning non polar molecules off of surfaces, alcohols, gasoline, lye, brake cleaner etc, but they’re not great at cleaning your hands because they strip the lipids that make up your skin off.
I worked on a Christmas tree lot through my winters as an undergrad and olive oil always worked well. Of course then you need soap and water to remove the olive oil.
“Magic All Natural Industrial Hand Cleaner (with walnut shells)”
Is downright the best thing I’ve ever encountered for cleaning anything on the hands. Anything sticky, greasy, non-newtonian… etc. it scrubs right off. Person who’s worked in grimy machine shops for 30 years introduced me to it. Fast Orange is a complete & utter disgrace comparatively.
Coffee grounds are nice, but walnut grounds are far superior.
I imagine there are variations in other places, I think it's mostly concentated citrus oils from oranges.
It the same for blood stains on clothing. They are not generally water soluble, you could get them out if you put it under cold water if the stain is still fresh. Hydrogen Peroxide can dissolve blood stains (fresh or old) since it can be used as a solvent.
Put differently, it breaks up the stain molecules into smaller molecules and causes other reactions that change them, it doesn't just dissolve them. You can dissolve resinous stuff with various solvents, you're right about that. Stays mostly the same, just goes into solution.