D
G
E
C
A
G
E
C
A
F
Besides pulling strings behind the bar, a major "trick" he uses is a back slant that brings the C string up to unison with the D and even more often, a forward slant that brings the D string up to the E. I stared at those videos a lot.
I would strongly suspect that Mike's special tuning* was the top 8 strings of Reece Anderson's non-pedal 12:
D
B
G
E
C
A
G
E
---
C
A
F
D
If it wasn't, that's still a bangin' tuning for this, with the two lower top strings and roughly four strings underneath for unison slants (depending on your bar length) - the opportunities for mischief abound.
*actually since he mentions C# and G#, his was probably the same relatively but with an E major base. Tonally you'd have -
2
7
5
3
1
6
5
3
