Teaching feeding manners to a toddler. Possible? How?

[OodneedsanOod]

I'm pretty sure it should be able to be done. He says please and sits nicely at the table so why does he bite and pull at my top and spin while he feeds?
If he bites he goes down. I ask if he wants milk and he says no ( no to everything at the moment!)
I've had a few occasions of 'uddle pwease' which was nice but the ripping at me isn't.
And the spinning

He's dc4. None of the others were this rough.

[YokoUhOh]

My DS (23mo) does this. He also boob-twiddles, which drives me crackers. I have started to walk away if he hurts me, is this an option for you?

[OodneedsanOod]

I often put him on the floor 'time out' style