Question: When chickens have been slaughtered, and they are still moving, they are immediately thrown into a large pan of boiling water, to make it easier to remove their feathers. If we do that, is it permissible to eat these chickens?

Answer: If that is after they have been slaughtered, there is nothing wrong with it (and they are halaal to eat), but you should not subject them to this torture.
Shaykh Muhammad ibn Saalih ibn ‘Uthaymeen