After finding out that Soygel is a nontoxic miracle for cleaning up my adhesive-caked heart of pine floor, I went out in search of cheaper-yet-effective brands of nontoxic solvents.
I ended up going with SoyClean Paint Stripper. At $31/gal, it is about half the price of Soygel. SoyClean is a liquid, which makes it a little harder to wrk with, but I got the hang of it pretty quickly. It does have a rather overpowering citrus scent to it. I'd rather smell th soybeans, personally. It works, but is not nearly as impressive on the adhesive as the the Soygel. As I have a gallon of it, I will be trying it next on the old paint splatters and varnish on my stairs. I think it will be able to handle that much better. I will report back after that experiment.