When they were supplied with our fifth wheel we used them. They had bright orange tags that hung down to remind you to remove them before sliding out. You could also put some kind of tag on the switch itself. I figured there was a reason they were supplied with the trailer.
Goody Two Shoes and the Filthy Beast
2008 Chevy Silverado 2500HD
Duramax and Allison 6 speed
2012 Wildcat 282RKX
You can't make things idiot proof, you can only make them idiot resistant.