> Uses DMSO (by-product of paper production processes) as solvent. It's pretty nasty.

Copying my comment on another subthread [0] here:

I've only ever personally used DMSO in chemistry labs, but Wikipedia [1] makes it look pretty safe: it claims that it has a higher LD50 than ethanol and that it's been FDA approved for human usage, so I wouldn't call it nasty. Now, I wouldn't really want to drink it because the side effects and taste sound pretty unpleasant, but it appears that it would be safe to do so.

[0]: https://news.ycombinator.com/item?id=46442253

[1]: https://en.wikipedia.org/wiki/Dimethyl_sulfoxide#Toxicity