[LightninBoy]

I use a bottle neck, and I like it loose. (On my pinky)
I keep my ring finger against it to stop it flying off.
I've never used a coricidin bottle, but I tried a little experiment to stop my bottle neck from turning around while I play.
If the seam of the bottle touches the strings, it scratches and makes a horrible noise, so I carefully lined the inside with masking tape.
It worked, but it was tricky to do.
(However, I don't like the way it feels, and I don't really need it anyway.)

It may be the answer to your problem though, as a coricidin bottle may be top heavy, and it may try to fly off your finger!
Hope this helps.
L.