If you want to cook at 250F, you are going to have to help the thighs along with rendering, many folks use the part of the Pickled Pig method which scrapes the fat off the skin and then replaces it. Some folks swear by mayonnaise as a coating.
My preference is to cook a lot hotter, at least 375F and up to 450F.
"perhaps...but then again...maybe not..."
careful there son, those ribs are boiling hot...
(='.'=) Here there be bunnies...
Pacific Rim BBQ
Bob's Brew and Que