I have to admit a great curiosity about these pre-shave oils. To me it would seem counterproductive to annoit the face with oils which would tend to interfere with water uptake in the whiskers, as it's (to my understanding) the moisture which softens the hairs. I also don't like anything even slightly slippery on my fingers, as oils -even lather- would be, that would compromise my grip on the razor.

My pre-shave preps with a hot water rinse, wash with soap, and hot water rinse at the sink, or a shower with the same routine followed with lathering and shaving are all I use. Perhaps I'm missing something, but it does seem to work OK.