I brought it to a brief near-boil (setting 8) for 3 minutes, then it simmered on a setting of '2' for about 4-5 hours, and then a setting of '1' for 4-5 more. Well below boiling.
I took it out of course, but now I wonder: is it safe to eat the rest of the pot?
I realllly want to eat it; it has yummy local collard greens, turnips, and pasture-raised pork. And it's delicious.
My best guess is that it wasn't really hot enough, for long enough, to create a level of exposure that's a measurable health risk in one pot of greens.
But if there's somebody here who works frequently with these materials (or who has recently refreshed themselves on the available evidence), I'd love to hear empirical thoughts.
Overall, if it was a brand new cloth or had previously been used to clean toxic chemicals like motor oil, you should discard all of the remaining food. If the cloth had only been used food spills and previously washed...I still wouldn't eat it, but I could see why someone who is more chancey with their food might.