Just to add on to dave's post, the way the video guy is using tri-tones is by taking the note you would normally play as the root, and substituting it with a tri-tone based solely off that root note.
The tri-tone substitute for any note will be the 3rd and b7. So, for the note C, we use the C major scale to find the 3rd and b7 notes. They are E and Bb respectively. When you make the substitution, any place that you would play a C in the bass/LH, you would play an E-Bb (or Bb-E) instead. The other chord is the F chord. The tri-tone sub for F would be the notes A and Eb.
This technique works great if you have a bass player who can play the actual root note, this way you won't be clashing with your sounds. And if you listen to the video, you will hear the pre-recorded bass notes being played.
Bonus: if you look at the tri-tone sub carefully, you will discover that it's a play off the dom7 chord. Example:
C7 chord = C-E-G-Bb
tri-tone sub for the note C = E-Bb.
So, you can actually figure out all the tri-tone subs by knowing all the dom7 chords.
C7 chord = C-E-G-Bb
C tri-tone = E-Bb