I'm so glad you put this question out there as I'm constantly on the hunt for 10 hour crock-pot recipes - - here is one I've tried and my family loves.
3+ lb Pork loin, 1 sliced onion (I’ve used white or Spanish), 1 ½ cup Chicken Broth, 1 ½ cup white wine, 1 tsp thyme, 1 tsp sage, salt and pepper.
Rub pork with salt and pepper, sprinkle thyme and sage on top. Put into crockpot and cover with onions, broth and wine. This can cook for 10 to 12 hours on low. When done remove loin and slowly add flour to remaining liquid for a really yummy gravy. I’ve served this over brown rice and egg noodles.
The original recipe called for browning the pork loin in a pan before putting it in the crock-pot -- I've never done this as I am scrambling as it is in the AM. Also, when I make this I use the largest pork loin I can find so this makes 2 meals (good on sandwiches or reheated).