Well, that is a good question. There are a whole range of scented oils and lubricants that can be used for sensual massages. But one must keep in mind that certain oils might not be natural and penetrating the vagina may cause irritation and inflammation. But in most case using lubricants to smooth the vaginal canal is not a bad idea and it does not cause any significant damage to the body as well. Water soluble oils and vegetables oils can be used for massaging the vagina as well. You need to use your fingers gently while massaging the vagina. Cheers!