I do a light rub, usually just salt & pepper, but sometimes some garlic powder added. Then I put them in the pit, unwrapped, at about 275* (only because that is a sweet spot for my UDS). When I get a decent color, they get wrapped and I take them until the meat probes tender.
After that, pull them, let them rest for 45 minutes or so wrapped up in a towel (I often put them in my Dutch oven), and feast away.
If undercooked, they will be dry, which is what I'm guessing you had happen. Especially if the fat didn't render.
Give them another go and be sure you get that probe tenderness.