although Celery has natural sodium and lots of other good things, this is only true of high-brix celery--low-brix, and the nutrient profile is very imbalanced. You can verify this yourself with a refractometer, and the subject as a whole is fascinating and eye-opening: it explains why people who eat a good, careful plant-based diet still crave more and more, and find they are acidic when they'd expect to be alkaline, to oversimplify: it's the balance of nutrients, minerals, etc. that they are missing.
I would be inclined to perhaps try a salt bath--with the pink stuff. (himalayan) Maybe kelp is what you are really craving--it has the whole spectrum, and the good sodium.
Nice sprikled on some salad...