Originally Posted by Airhead Wrangler
The only kicker is that the hydraulic clutches use mineral oil rather than more widely available DOT 3 or 5. Anything else will eat the seals. You might be able to get away with some kind of cooking oil in a pinch if you had to drain and rebleed the system for whatever reason.
A friend experimented with baby oil in the hydraulic clutch on his KTM 640, as I remember, he suffered no ill effect from using this very common mineral oil. Hillbilly repairs might be possible with a grocery nearby.