If you are using just baking soda with salt and/or water, it will solidify. I use baking soda & vinegar. It doesn't take much, about the same of each, sometimes a little more vinegar. The foaming dissolves the baking soda. You also need to run water for a minute or so after it quits foaming to clear everything out. Have used this for 2oyrs. No problems. Hope this helps. ... View related article.
