I pull the hides from the girls cages when I start pairing them up ... over the years it has proven to be very effective for me.
BUT, there is ALWAYS an exception to every rule ... for some extra shy girls, I add extra crumpled up newspaper to their tubs to help them feel secure having no hide.
It's extremely important to know your snakes and make husbandry descisions based on their needs ... and not on some type of blanket advice given on a message board or in a book or video.
-adam