I'd never ever feed a horse to keep it occupied if it fidgets. A horse should know that he has to stand for grooming, which, by the way, should be enjoyable. No pawing, dancing around, none of that is acceptable.
My horse came to me as a paw-er. After about 3 minutes in the crossties she'd start pawing and scraping her hoof on the ground. If I was close enough, I'd give her a firm "NO" and whack the shoulder that is attached to the pawing leg. Then I asked her to stand. If I was out of reach or down the aisle, I'd again give a loud firm "NO" while placing one loud stomp on the ground. Then I'd ask her to stand. It took about 5 days for her to stand like a lady.
I can put her in crossties and wander off and do something else and she'll stand for a very long time. She loves being groomed, and she really gets into it.
Just a thought-- a horse that hates grooming and offers to bite/kick when grooming the barrel area is showing you major warning signs of gastric ulcers.