I did, and I find the old urine very helpful. I notice the condition gets worse if I forget to do it.
I use both fresh and old urine with my sonic toothbrush. Have to be careful not to swallow the old urine and to rinse afterward, also not to inhale it too much. But the taste and feel in the mouth is not bad at all, it's actually quite refreshing.
At night, when I no longer drink the urine, I put fresh urine in my water pic. Afterward, I fill the machine with tap water to flush out the urine--though by next evening, any urine left in the machine would be ammonia and antiseptic I believe.
I haven't tried the Schulz products (ordered them two weeks ago, and they have not arrived) but the best product I have used is the combination of coconut oil (put it directly on the brush) dipped into a tooth powder product called "good gums". It's when I ran out of it a few months ago, and couldn't get a refill, that my gums flared badly again.
I've started using propolis mixed with urine as a rinse, but haven't found it to make a large difference. The thicker propolis though, the 70%, combined with honey, sticks between the teeth and on the gums, and as honey is actually helpful for fighting infection, I do feel that this combo, once a day, is proving helpful. It sticks behind the teeth for a while but maybe that's a good thing... the propolis keeps the honey longer on the spot that needs healing, along with the antipathogenic affect of the propolis itself.
HTH. BTW, I've started with emotional freedom tapping (demos on youtube--super easy) and I believe it's helping all the protocols have their best effect.