Last year, he was quoted as saying "Luckily, I don’t snort, er, cocaine! It’s just not my thing.”
Kind of a weird thing to say. Most people would say "I don't use cocaine" or "I don't do cocaine". But using the word "snort" to remain truthful, and then being caught on camera rubbing coke on his gums seems pretty clear.
I'd go as far to say that's 99% cocaine and maybe 1% that it's a zyn or something else.
His thumb is un-tucked well before his hand (with only one finger extended) reaches his mouth. He's not pinching it between any other fingers, as only his index finger is raised... so how exactly did he insert the zyn with one finger?