You are the only person that I have communicated with - anywhere - that expeieenced the intense sight of the bubbling- I call it "hydogen peroxide thing" in the toilet. I had used powdered sulphur on spot on my head and then later treated my hair with pyretherin based shampoo...It happened to me 5 times..in my urine! I was horrified and thought I was losing my mind...so thanks for sharing..