We're approaching the 24th hour of Stephon Marbury's absolutely nonsensical web-rant -- and now the basketball star is resorting to eating Vaseline right out of the jar.

Still not wearing a shirt, Marbury -- who insists he's neither on drugs nor out of his mind -- threw down a finger-full of the petroleum jelly ... and then declared he wanted someone to write him a check for "a billion dollars" so he could start his own TV network "like Oprah."

For the record, we contacted the good people at Vaseline about the incident, who told us "Vaseline is for external use only -- it is not intended for eating ... I don't know what he's trying to prove."

Neither do we.