The Bamboozler badge is for "Distracting 50 enemies with throwables"
You can distract an enemy by using a throwable within hearing range, as soon as they deviate from there pathing it will count.
This can be farmed pretty effectively on the "Kill the snitch" trial as there are several enemies early on that can be distracted and reset. Using the stun Rig can optimise this as it is an effective distractor and as it recharges can be used infinitely.
Also two handy things to note:
1. The in-game badge menu tracks your progress.
2. Leaving a trial after gaining progress still counts towards it.
Video guide for reference: