Pattabhi Jois always recommended that students of Ashtanga Yoga take an oil-bath on their rest day (usually Saturday). Castor-oil, when applied to the head and body, removes the excess heat from the body. This heat builds up over the week of daily practice and, according to the Ayurvedic tradition, excess heat can cause disease in the body.
The name ‘oil-bath’ can be a little misleading to westerners as it’s not a bath as we would think of it. Rather, the oil is applied to the head and body and later removed in the shower. It is more akin to an Indian-style bucket-bath, but we don’t need to go there in this post.
Kimberley (Kiki) Flynn has written an excellent article on how to do the oil-bath and has even made a couple of videos which I’ve included below, so I won’t go into the details here (she has explained it perfectly already). I should just mention that I have found it impossible to get soap-nut powder and ‘green powder’ in this part of the world, but that pure neem soap works almost as well for removing the oil (almost!). Please do follow her guidelines on the length of time you leave the oil on for, as this is very important.
If you don’t want to use castor oil then Pattabhi Jois also recommended almond oil, which is a lighter oil and is easier to remove (normal soap is ok for this), but I think the castor-oil, if you can get it, is the best. The process can be a little bit messy but the benefits are really great. Sesame-oil is also recommended by many ayurvedic doctors but that is lighter than almond-oil and is more for daily-use rather than what we are talking about here (removal of excess heat built up over the week). If you do use almond-oil or sesame-oil make sure it’s not the toasted kind.
Castor oil is available at most health food shops as is the neem soap (get the max strength stuff).