Not really sure what the spoon is supposed to be showing, but the practice looks like grade A hoss feathers. Probably nothing wrong with it, although I'm sure there are some shysters out there hawking their double extracted certified aryuvedic yak oil for optimal results. The hidden cost of stuff like this is the erosion of critical thinking in the public (there is a cause:effect problem here that I'm grappling with) - when someone tries it because it might work, and through chance, selection bias, and the quirks of human memory it seems to work - then they slip into the conspiracy theory fantasy that "alternative medicine" types are promoting.
Brushing ones teeth to improve dental hygiene works for a couple reasons. Mechanical removal of plaque, the soap effect of some of the ingredients of tooth paste, removal of trace carbohydrates (sugars and starches) that oral bacteria can feed on, and strengthening of the connective tissue in the gums around your teeth (again, largely a mechanical effect). Swishing oil in your mouth doesn't do any of those things. There is a logical fallacy in the argument as well, a variation on the appeal to authority sometimes called the appeal to antiquity. Just because something has been around a long time is not evidence of it working; it is evidence of pre-scientific magical thinking and a lack of immediate lethality.