Conn, honest to God, I've had teeth filled & slao pulled out, without any form of anesthetic - no problem! But when it comes to yon cleaning business? - Hate it and could just run out!!
But, look on the bright side, as said by others, simply think, "Sure it will be ALL over in less than 8 - 10 minutes"
& You will look at your pearly whites afterwards and say - "What a smile Kid!"
Just go for it & if your knocked out, more the reason to get it done!! Don't worry pet, all will be well!