They are basically a brilliant solution and my fave.
I like Dunlops too, they are simple to use and you can trust them staying together, they can sometimes be a bit of a pain to fit together but once they are on they are on.
Schaller I've not enjoyed so much, while the the Dunlops are lightweight, wide and fairly flat, the Schaller's extend out more and are heavier, I've had them swing about and whack into the finish of the bass... my main problem has been the nut works it's way loose- and when that happens it's worse than a strap coming off as it's less expected and more sudden. The new design looks to have addressed that flaw though.
But Grolsch - or any other bottle with a swing top will work. Posh lemonade should work too.