Incidentally I'm glad Omega are now using that coin edge style keying on their new watches instead of the six notches, surely people will look at it now and think "Damn, pliers just ain't gonna lick' it".
I use instant glue all the time. Can't fault it - immense area of grip for friction, no chance of scratching anything, easy to clean off... Wouldn't use it on a watch with an enamel medallion on the back, though 😁
Crazy glue works as well - just soak in acetone after to get the nut off and clean the case back.