Chops Duster! - Fingerbuster!
A "fingerbuster" could be considered as an instrumentalist's version of a "tongue-twister" which is usually defined as a group of words, or a phrase, that is considered to be difficult to execute.
While the degree of difficulty varies with both the phrase and the ability of the practitioner, constant repetition, in any case, at a slowed down tempo, usually serves to iron undo the knots before gradually bringing it back up to speed.
This particular "finger-twister" appeared out of the blue recently while I was doing my saxophonistic due diligence, and it gave me "the finger".
The pattern here is deceptively simple:
Two measures and 4 groups of eighth notes, consisting of 3-b7-8-3, 4-b7-8-4, 5-b7-8-5, 4-b7-8-4.
This configuration has a basic mixolydian dominant 7 - sus 7 - sound, in and of itself. Like most "finger-twisters", there is repetition involved, with scale steps 3 - 4 & 5 moving back and forth against steps b7 - 8, which remain constant as the second two notes within each 4 note grouping.
As the level of difficulty probably varies with the instrument involved (guitarists, keyboardists, bassists, trombonists, as well as trumpeters), I'd suggest starting out at a "slow enough" tempo (whatever that might mean to you) and gradually increase the speed each time you play the 2 bar phrase, say, 4 times without a mistake, and feel comfortable with it.
Then, move on to the next key, which is presented here in ascending chromatic order.
Once you've straightened out a few knuckles, try altering some of the notes.
For example, make scale step 4 a #4 (Lydian Dominant). Change scale step b7 to a natural 7.
Dust 'em, don't bust 'em!