I don't think there is any prohibition against discussing things medical in general; it's when diagnoses or specific medical advice comes around that it gets a bit murky.
I might think that spinning diatoms might be the best use for that. Urine isn't necessarily sterile, nor does a high bacterial load need to be there for a bacterial infection to exist. I have a daughter with a rare genetic variant that causes her to have an unusually high urine ph and her urine is never sterile. She is carrying a persistent low grade infection almost perpetually and has been since birth. If you were to spin her urine in that device, almost always it would show no major problem, so she would go untreated. The problem with that device is that it is based on a simplistic model of bacteriology, how urinary tract infections progress and why they are becoming more difficult to diagnose and treat. Many labs don't even do a good job of diagnosis.
The basic problem is, and this is also true of many other conditions of even partial bacterial etiology , that bacteria do not necessarily have a single morphology. They have many morphologies which have evolved as techniques with which to survive during times of environmental stress. One of them is the ability to shed cell walls ; another the ability to develop biofilms. When penicillin arrived, it mimicked the effect that various fungal enzymes have on bacteria, that of dissolving the cell wall and therefore allowing the contents of the bacteria to be vulnerable . However, certain individual cells would exist as a cell wall deficient form or morph to that maintaining a membrane invulnerable to the enzyme and thus survive , only to revert back and grow a healthy population in the future. As time went on and more and more penicillin was used, more and more species learned to utilize what had been originally a survival mechanism, as a matter of course and low grade infections of sequestered and atypical bacterial forms have become commonplace, rising and subsiding at times and always difficult to diagnose or treat effectively.
That device would only be of value for an obvious first case infection but be useless as a diagnostic tool for recurring or persistent infections, which are in fact the ones that contribute to the spike in UTI rates.
Gerald Domingue spent most of his career piecing together the puzzle, that sadly still goes unnoticed by many practitioners. Some brief historical information from wikipedia.