Waist trainers

Chef Cara • Currently cook for a fine dining restaurant in Traverse City. Single, 29, chef, would love to be a mom someday.
I keep hearing a lot of talk about waist trainers. I've been looking online trying to do my research but I'm not sure where to start. I would like to get different opinions from those who wear/wore them also. Does anyone on here wear them? Do they work? and where can I get a good quality one for a great price? and anything else I should know about them