Find out if it is mostly or all castor.  If it is blended with petroleum it may not mix very well with alcohol.  I used something called Blendzall a number of times, a prepackaged castor oil with additives.  It worked fine.

We use to use Castrol in our Motocross bikes... haven't seen it on the shelves for many years. I do remember that it smelled good but also remember that inhaled Castor Oil worked the same as if ingested! 

I Think we need to be careful, the site is for Castrol which can be anything. Castor oil and Castrol sound very similar but are not. I use Castrol in my vehicles but it's not "CASTOR"

I was talking about 100% Castor oil based lubricants that were sold here in the U.S. up until  the mid to late 70's. Mostly used by the motorcycle crowd either pre-mixed in gasoline or injected. I think the popularity of synthetics along with the fact that synthetics burned cleaner and were  touted as having better lubrication properties lead to the decline of this product. Cost was relatively close if I remember correctly.

The Castrol M being discussed looks to be 100% bean oil.

http://129.35.64.91/bpglis/lsdsukf.nsf/0/85FE431DB24AC01880256D900043D16D/$file/000795.pdf

I think we yanks started getting our oil from Pennsylvania  first. They were chasing cows and shooting each other in Texas back then... come to think of it they still do!