Did you know that at Australia Zoo they use a garbage can lid? For the really big guys. They go in the enclosure of the burmese and keep it focused on the can lid. Move it from side to side and if the snake moves and tries to direct its attention on the handler they just keep the can lid directly in front of its face. If they are moving the snake a couple people grab the snake and start walking through the park while a third person holds the can lid and just keeps it in front of the snakes face. They walk along and its the lid holders job to keep the lid in front of the face and keep it distracted. Kind of like shield.
This way they never need to hold the snake behind the head which causes alot of stress and anger. They dont get bitten and they dont stress the snake either.