I admire your academic approach in general but it's overkill for oil pulling. Seriously how hazardous could swishing organic oils around in your really mouth be?
That said, if you're allergic to an oil or it's rancid or overly acidic - you COULD have a bad reaction. Also OP tends to rid your gums of swelling which can make them look thinner; which can be alarming at first.
In general though, just go Kamikaze with the stuff and try it. Even if you're one of the rare people that get a reaction, it's easily cured by just stopping temporarily (or permanently if you prefer). For most people it's by far the best thing they've ever done for their gums.