Bushman's hanky

[Rihanna]

The process of [clearing] ones nose without the assistance of tissues, hankies etc etc
More specifically, clearing ones nose by pushing one [nostril] down with the index finger and blowing out of opened nostril, subsequently shooting snot straight to the ground. The bushmans hanky must be executed with a fair level of pressure or the snot will end up smeared or looped around the nostril (it may even [lodge] somewhere on the lower cheek or mouth region) rather than on the ground where it belongs.