When I was 15 I used aloe vera goo from the plant I had in my room at the time. I was just using fingers, so it wasn't too bad. Now I know better and buy the real deal.
Still, I wonder how that'd work for partner sex. I think I'll pass, though.
I was 15-ish and decided to try anal. All I had was massage oil (I knew at 12 that I wanted to be a massage therapist so my mom bought me lots of books, lotions, oils and the like.) so I gave it a go. It wasn't thick enough, but aside from a bit of aching later I didn't have anything *bad* come from it. It was a carrier oil and food-safe so I can't imagine anything terrible would have come from it anyways, but still. Not so good. xD