Here's the link, incidentally:
https://www.vmsherp.com/LCNotEating.htm
I've fed lots of colubrid & rosy boa hatchlings myself for years, & I personally have never found "braining" to be of help, & besides, it's gross.
As I've said many times, it's easier (& a little less gross) to just pinch-damage the nose of the feeder with a firm squeeze of the feeding tongs-
this releases more scent in a similar way, & helps to steer the snake to swallow the head first (without too much damage that can make it harder).