I'd like to say, I have been swishing with old urine. It gets bubbly and does not taste bad at all. It is very soothing. With repeated use, my resistance is less and I can appreciate the healing effect of this alkaline liquid.
I read on the yahoo forum, one of the Indian experts mentioned that 8 week old urine is best for perio disease.
I'll be getting some propolis soon, and will see if adding it to old urine is stronger still, while smelling less, as so many here say.
I am also going to try a homeopathic concentration.