Toasted sesame is not recommended for OP. Although I used it the first couple of times when I started a year ago until i could get to the store. I don't remember my teeth being stained from it.
Olive oil has been reported to stain teeth as well but I never noticed it. The best for whitening seems to be coconut oil.
Are you sure your teeth haven't lightened to the yellow stage? Sometimes we don't notice coffee or tea stains until they start to lift.
Are you doing a search in the archives? There's lots of good info stored there.
The stain will come off with the proper oil for OP. The proper oils are nut or seed, untoasted, unrefined, cold or expeller pressed. Organic if you can get it.
Coconut oil will probably be your best bet right now if you can get your hands on it. I always found it had a super whitener effect. My first love is unrefined, untoasted sesame oil. Walnut oil is really good too.
Swish twice a day if you can (morning and just before dinner). Not too late at night because sometimes OP has been know to stimulate.
Proper OP will take that stain off and will start to really whiten your teeth beyond. I'd give it a few days to a couple of weeks to really start to notice. Yes, it can be very fast.
I stopped using toasted sesame oil and switched to cold-pressed grapeseed oil (which I always have) with 1-2 drops of oregano oil.
Yesterday I bought cold-pressed extra virgin coconut (had a hard time finding it) and started to OP with it last night.
I have been doing OP twice a day. The yellow stain from the toasted sesame oil hasn't come off yet, but I think my teeth is getting somewhat whiter (can't be too sure about this since the result isn't obvious enough). Hope the yellow stain will come off in a week or two.
(The label of the sesame oil that I unfortunately used says "Pure Sesame Seed Oil". I hope there is no added color to it. Otherwise, I may have real difficulty in getting rid of the yellow stain.)
Once I did mouth rinsing with 20 drops of MMS , because of tootha pain and gum bleeding, and after all my teeth turned yellow. But tha pain and bleeding was gone. This yellow coloration on teeth lasted for 2-3 weeks, and than it turned back to normal.