You can find pine tar at horse supply places. They use it on hooves some times. You can also order it on Amazon. Be very careful you get something that is 100% pine tar! It will make a chocolate-colored soap that smells very piney and also (IMO) smells a bit medicinal. Some people think it smells smokey. Pine tar soap is an old folk remedy for all kinds of skin conditions.
If you search the forum for pine tar soap, you will see lots of threads, recipes, discussions, etc. I don't want to summarize those threads, but I am happy to tell you about my experiences.
25% is too much. 6 months later the soap is STILL soft and gooey!
20% is okay.
My recipe is something like 40% lard, 20% coconut, 30% olive oil, 5% castor and 5% sunflower. This works fine for pine tar soap. I increase the water percentage from 38 to 40% (using soapcalc). I also use lavender EO.
DO NOT STICK BLEND! Pine tar soap traces VERY VERY fast! It's comparable to clove EO.
I heat the little can in a saucepan with some water, then pour the pine tar into the oils. I stir the oils and pine tar with a large paint stirrer (free from Home Depot), then add my lye water, then stir with the paint stirrer. I use cardboard milk cartons as molds. Which is good, since my last attempt is STILL in the mold! I prefer to use as many disposable things as I can, so I don't have to get pine tar off of anything.