I can only ASSume that you are a member at Costco. Conditioner is meant for external use and full of other ingredients that I'd rather not try putting into anyones ass for a lube. My wife and I were at Costco yesterday, they sell a very large jar of pure cocoanut butter for about $16. All you'll need, it's all natural, smells good and lasts a long time without having to reapply.
Many products absorb into the skin, the body's largest organ. I try never to put anything on my skin that I wouldn't eat! With that in mind, I do carry an all Natural Numbing Lubricant Oil in my store.
One big reason to not use conditioner is any scent, even unscented lotions, conditioners and even massage lotions have essential oils that can be really, really obvious on tender tissues like mucus membranes, like the anal canal.
At minimum you could just use lotion if you don't want to get lube for sex. Conditioner is meant to be rinsed off, it may not be safe to get it in the rectum where it could EASILY enter her blood stream. Even cooking oil, shortening, or butter would be a better choice before conditioner. There is a good choice at least ONE of those items is in your/her house.
