Cheap shave oils contain mineral oil (liquid petroleum)- which is unfragranced baby oil, this is a by product of petroleum. A good shave oil is usually made of Sweet Almond, Apricot Kernel or Grape seed oil or various Essential oils. I always use shave oil as a part of my shave.
A bit late to reply, but... I tried a shave oil (actually just a nice lemon-scented almond & Vitamin E oil). It definitely improved the shave--very smooth--but I got nervous about it being bad for my skin (my skin is very sensitive to oils) and didn't want to worry about it getting on my razor and brush.
I've used a sample of the AOS Pre-shave oil and didn't care for it. Felt like I was putting 10W30 on my face. I did get a good shave though although this stuff is expensive.
As stated earlier the AoS pre-shave oil is just a blend of castor oil and olive oil with clove essential oil (and maybe other EOs, I forget). One need not spend a fortune on a pre-shave oil. A few drops of olive, grape seed oil, jojoba oil, almond oil (to name a few) will work. Castor oil alone is to thick for my taste but can be blended down with any of the above. It only takes a few drops rubbed in well. The goal is to keep the skin supple (so it will move under the blade) and not to be a "lubricant." I think some people are overdoing the oil. If one is in doubt, try a scant amount of extra-virgin olive oil well rubbed into the skin. It works for me, YMMV. Bill
