You've missed the most obviously effective mixer for urine.

"Egyptian physicians used human and animal excrement as a cure-all remedy for diseases and injuries. According to 1500 B.C.’s Ebers Papyrus, donkey, dog, gazelle and fly dung were all celebrated for their healing properties and their ability to ward off bad spirits. While these repugnant remedies may have occasionally led to tetanus and other infections, they probably weren’t entirely ineffective—research shows the microflora found in some types of animal dung contain antibiotic substances."

So have that long handled scoop ready, and go Back to the Future to save us from COVID19.

https://www.history.com/news/7-unusual-ancient-medical-techniques