OP completely took away my tooth sensitivity. I couldn't drink anything acidic prior to OP, my teeth would ache. I was really freaked out about this and was sure I was looking at a huge dental bill. I even started to have dreams that my teeth were falling out.
I'm here to say to you that OP was the thing that reversed all of that.
So does it hurt enamel? Hundreds and hundreds of testimonials here and at Earthclinic and all over the net should be enough to convince you that no, it does not hurt your enamel.
After I OP I gargle three times with warm Sea Salt
water. It really cleans out your mouth, and your mouth will feel fresher than brushing.
What kind of toothpaste do you use?
I don't know the PH of sesame oil, but I do know that OP will rid your mouth of the bacteria which is acidic.