[Ruy Dias de Bivar]

DMSO. I remember when lots of QUACKS were trying to sell it as a cure all in the 1970s.

[The Duke]

DMSO is used by vets to treat horses, both topically and (apparently) internally. It also has the property that it somehow drives other substances into the body through the skin, which some have said is therapeutic (I guess that depends on what it's used with). I got all this from a Google search on "DMSO horses".

It's interesting.