So this is probably a really stupid question and I bet I should ask it on the eventing board, but I was watching some videos of horses doing the cross country stuff covered in what looked like Crisco cooking oil - the thick white goopey stuff!
It's supposed to help the horse slide across a jump if it needs to. The irony is that according to studies that have been done, the horse's own hair actually is more slippery on it's own. People like it though, helps to make you feel like you are doing everything you can to help.
Crisco was perhaps used in a pinch, years ago. There are specifically-formulated products, now. Much easier to wash off and get the pony clean for a Sunday jog.
It does help a horse slide over a solid obstacle if he leaves a leg or drags a stifle. Not really for "prickly" brush, that doesn't really hurt them and they brush through easily. Think more along the lines of a big solid log dropping into water... it's not uncommon to rub a stifle, and grease can prevent some hair loss and save the skin. Watch here as lots of horses "slither" over the log atop the mound. (NOTE: the slightly scary trips seen here are not "normal." This obstacle caught MANY horses very off-guard, as there was very little "up" to the mound, and horses were greatly surprised at the steep descent and water below.)
Frequently, though, much of the grease has melted off by the time the horse has finished, after splashing through multiple water jumps.
“A clever person solves a problem. A wise person avoids it.”
? Albert Einstein
No it's not crisco, but it is basically a grease. Helps the horse slide over a fence if they drag a leg or something. I think it's called eventing grease, now. (and it's water soluble, i imagine, as crisco would not allow them to sweat and make them even hotter)