Heh. 
Púca, little troublemaker. One more.
Merlyn passed away on Dec. 30.
I don’t know about household alternatives (lemon etc.) but many years back, we had a cat who developed a pathological licking issue - he licked a spot on his right side raw to the point where we had to have a chunk of skin removed surgically. This was after numerous attempts to stop it by steroid injections. They put metal stitches in the incision to keep him from licking… and the day those stitches came out, he was right back at it.
So the poor fellow wore an Elizabethan collar for several months. Finally someone at the vet suggested we try the bandage-protection spray (may have been bitter apple, may have been something else; this was 20+ years ago so I don’t recall).
One spritz.
One lick.
Kitty hiding under the table, foaming at the mouth.
Next day: one spritz. One lick. Under the table foaming at the mouth.
Never licked again.
Now, this cat had feline leukemia when we got him. And perhaps a year after the last spritz, his front leg on that side became very weak and atrophied. So in hindsight we think the licking was a manifestation of some spinal issue related to the feline leukemia. Poor beast probably had a phantom itch that Would. Not. Stop.
Still, the spray gave him greatly increased comfort for his last year (we had him euthanized a month or so after we saw the limping - he’d given up eating, was losing weight, had very little joy in his life).
Anyway - if you google “household alternatives bitter apple” you’ll get some hits, if you choose to go that route. Obviously try to think if there’ve been any changes in the environment, new pets, new cleaning routines / chemicals, any possibility your cat is being “harassed” by another animal who shows up outside your window to taunt him?