Answer: Many natural vegetable oils can be used for sexual purposes, though they may be messy or stain fabrics. Pure vegetable oils like Wesson or Crisco will work, as does olive oil. Any cooking oil may work; if it is safe to eat, it is likely safe to apply to your vulva. It may be best to use just a little at first to see if it irritates your delicate vulvar and vaginal tissues. You can also use mineral oil. Avoid scented and colored products. Baby oil while readily available contains scents.
Petroleum based products like Vaseline should not be used to lubricate the vagina, internally, as they may coat the vaginal walls resulting in infection. They also cause condoms to break down and fail. Mineral oil is also petroleum-based, but is frequently recommended as a sexual lubricant, and is contained in many lotions and lubricants. All lubricants containing oil, when used inside the vagina, may remain there after sex for a period of time, as the body does not have a means of washing them away. I must admit there is some confusion and conflict in regard to the advice provided concerning the use of lubricants containing petroleum and oils. Ultimately, each individual needs to be aware that the use of these products MAY cause vaginal infections, but individual experiences WILL vary.
Caution: Oil-based lubricants like petroleum jelly, body lotion, baby oil, cooking oil and mineral oil cause rapid deterioration of latex condoms and greatly increase the risk of breakage. Mineral oil, a common ingredient of hand lotions and other lubricants, can cause a 90 percent decline in condom strength in as little as 60 seconds. Oil-based lubricants are safe only with polyurethane condoms. In addition, do not use oil-based vaginal medications or lubricants when you are using a diaphragm or cap. Lubricants containing oil will also break down sex toys containing latex.
For additional information on lubricants please see the article about sexually stimulating the vagina.