First, remove the chicken from the package. No need to use oil. Unless you're letting the chicken sit and dry out there is no reason the seasoning won't stick.
Combine all the spices for the rub listed. Generously cover the chicken thighs with the seasoning. Coat them completely in the seasoning. I made sure the salt levels were perfect to avoid any worrying.
In the crockpot, add the seasoning chicken thighs then cover in the barbecue sauce. This is all you need because the chicken will release it's natural juices while cooking.
Cover the crockpot with a lid then cook on high for 3 hours or low for 5-6. When chicken is done allow to cool a bit before serving. Chicken is done at 165F but I suggest pushing the chicken thighs to 180-185F for more tender meat.
Quick tip, place the chicken on a sheet pan in the oven on broil for 5 minutes to thicken the sauce even more.