Pat the drumsticks dry and season generously all over with your rub or salt and pepper. For the crispest skin, season and let them rest uncovered in the fridge one to two hours, or up to overnight. Optional, but worth it.
Set the Kamado up for two zones: foil-wrap a diffuser and place it under one half, leaving the other half open for direct heat. Bring the grill to 400F.
Hang the drumsticks on the rack (a dozen fits; stack a few on top if you need to) and set the rack over the diffused, indirect side.
If you like, cook something else over the direct side: burgers, steaks, or a few ears of corn.
Roast 20 to 30 minutes, until the skin is crisp and the internal temperature at the thickest part reads 170 to 175F. If the bottoms char faster than you'd like, slide a doubled-over piece of foil underneath.
Pull at 170 to 175F (carryover adds a few more degrees). Rest a few minutes and serve.