K well first off i think that sandor clegane isnt feeding the worms...the hound is.The friar brienne and company meets near the mouth of ruby ford says the hound is dead.Then proceeds to take them to the monastary to meet the head priest reknown for his healing skills.On the way up they see a huge novice digging a grave and continue on where they meet the soldier turned priest,who does confirm the hound is dead that he buried him hisself.later he mentions the grave digger again for no good reason...i believe the grave digger to be sandor clegane he may have adopted another name at the monastary to protect him but this priest healed his face of the burns and his heart of the ravages of his past...this is the jist of what i remember some small details maybe incorrect but the meat of my guess is there.