do a search for "Breathe Ease XL" on the web, and you should get a few different places that sell it. I like it because it is FAR less irritating than using Kosher Salt. It really does work a lot better.
The local drug store (Walgreen's, CVS, Eckards, etc.) or chemist should be able to order Alkalol for you. I just ordered some a week ago. Costs about $4 a bottle when ordered this way. It can also be purchased online for less.
Alkalol can be used in irrigation, or gargled. For me, it takes the place of a decongestant. I can't handle decongestants like Allegra-D and Sudafed. They dry out my entire throat, make me hoarse, and keep me up all night (not to mention send my blood pressure up about 30 points).