Lori recommends using the jasmine oil from the neck down in her instructional videos. Exceptions being where a client has sensitive skin and problems such as lifting (with good technique). I always use my products as intended/instructed by the manufacturer. After all, it's in their best interest for you to get the best result!
I understand why some geeks choose to use the oil on the face. As i use hard was for all facial waxing it is adhering to the hair, not skin and is less of a concern (than on body). Also I find I can pickup more of the fine soft growth without it. That's just me though! X