What I did was buy a regular cat collar but very stretchy so if it got caught it would just come off. I had a breakaway collar before that, and thank GOD I was home when Oscar was grooming his chest and his lower jaw got caught in it!

I shake the Feliway bottle, put one finger under the collar, put the spray nozzle close and squeeze a blot of the Feliway into the collar. Takes 10 times longer to type this than it takes to do it.

It took Oscar a couple of days to get used to the routine, but after that it was feed, he's crunching, I spray the collar.

I like the idea of the pre-made collars, but would want a stretchy one. Or, I guess, make sure it's snug enough.