For those that believe it's “necessary” to doodle-tongue or double-tongue to play quickly. They are great techniques to practice but if you work on your single tongue and partial breaks you can
OTJ: Multiple Tonguing for Trombonists
How to Doodle Tongue on Trombone (Jazz Trombone Double Tongue vs. Doodle Tongue) - YouTube
OTJ: Multiple Tonguing for Trombonists
New Directions in Tonguing by Burke, James - qPress