Hi welcome to YT! You have found a place filled with knowledgeable, caring, fun yorkie owners.
My Bubba loves to lay on the back of the couch too
I would take Buddy to the vet & have his skin checked if he is licking like that - although I know sometimes licking is some type of OCD behavior that can occur in pets - my Bubba has licked upholstery before.
Also, I'm wondering if the horrid bath fear & the licking are related - I'm wondering what you are using for shampoo to bathe him. Perhaps it irritates his skin