Very similar to how they have sign language guys everywhere now.

It's the Jedi hand wave. Mind control.

The hand wave provides a momentary distraction that briefly interrupts the subjects train of thought. During the duration where the mind is unfocused the Jedi is able to implant a suggestion which would otherwise be recognized as foreign.

The lack of finesse compared to a Jedi is interesting. Perhaps he does it awkwardly because he doesn't realize what technique he's actually using, only that he has seen others do it and then uses it himself probably to distract you or fill in for his inability to fluently express his ideas because he is having to filter the ideas since they contain mischief.

He will also sip from a drink to signify "swallowing the bullshit".