Target, home section, contained sea salt.
Nice glass container with wide mouth and cork.
Just drill hole in cork. I am sure that a rubber stopper can be found in the same size.
Bottle can be removed, without taking doser off rack. You probably will pay just as much for a glass container from the bit of looking i did. Buy salt and bottle is free, or buy bottle and salt is free?
**Warning do not use the sea salt in aquarium**
Ed