Yup, it really works
The oil stops the wax from sticking to the skin, and can be used with any brand and any type of wax (soft wax, hard/hot wax, cream, honey, etc).
You really do only need a light smear on the skin - too much and the wax will slide off (if this happens, it's easy enough to just blot the skin with a tissue and try again). Some manufacturers sell specific pre-depilatory oils, but any light massage oil will do the job.
The French have been using this trick for years (they know a thing or two about waxing!) and it was in fact a French waxing brand called Perron Rigot that first brought it to my attention in the UK. Across the Atlantic, waxing stars like Lori Nestore (aka The Wax Queen) and our very own Anita (Huberella) have also been advocating the use of oil for some time now.
I find it helps the wax release better from the skin and reduces discomfort for clients, and I use it under strip and hard wax on all areas of the body. It also makes cleanup easier. Takes a while to get the hang of, but well worth the effort
Andy x