I use Sludge Dip & Go, and it holds on pretty tight to the large beads I make. The only time usually have a hard time getting my beads off is if I've been in a hurry, and didn't preheat my mandrel enough before applying the glass. The mandrel needs to come to a slight glow, then get the glass on there before it cools too much.
Also, too much heating and cooling of the bead release will weaken it.
There is some really good info on bead release (and other things) in this
Arrow Springs Tips & Tricks. I would think it would apply to most releases. It is in PDF format, so you'll have to download from their link, but it is worth taking a look at.