In that vein, I remember reading that a certain country taught their soldiers to wash in urine after sexual relations to prevent contracting social diseases.

Is this a bacterial colonization of the bladder without symptoms? Are the scientists arguing that these are normal bladder flora, in the sense that the colon has lots of symbiotic bacteria present? Are they saying that subclinical bacterial infection is widespread?
The bugs identified are not familiar UTI culprits. I understand the finding, but not the pathophysiology.

Well, they're saying both. The popular idea was that in healthy people, urine (and by association, the bladder) was devoid of bacteria because studies (or who knows, maybe just one study) were not able to culture anything. But they tried culturing urine in various ways and found multitudes of bacteria in healthy urine.

They're also saying that after they were able to successfully culture bacteria from urine, some strains seem more common in people with certain bladder conditions, raising the possibility that there is connection with the condition, such as "overactive bladder". If H. pylori bacteria can cause ulcers, it's not a stretch to believe that certain bladder problems can also have a bacterial cause.

IIRC, all the urine that goes into the bladder is filtered at the molecular level by the kidney; absent kidney infection, it ought to be bacteria-free. The bladder is emptied, mostly, on a regular basis, though many folks have some residual urine after voiding, and some have a lot. Bacteria can get into the bladder moving up the urethra, hence bladder infections, honeymoon cystitis, and the like. So, some bacteria are moving upstream, setting up housekeeping in the residual urine, sometimes irritating the bladder enough to cause spasms, sometimes not causing any symptoms at all. And these bacteria are stealthy enough to escape detection in routine microscopic urinalysis and routine urine culture. Interesting!

Interesting. Do probiotics work to help control these bacteria?

There is some evidence that probiotics can improve bladder issues, but it's still an open question. The reason they help may not be so obvious. The bacteria in the probiotic don't somehow travel from your digestive system into your bladder.

Probiotics may help by doing things like improving the body's immune system so it regulates the bacteria in the bladder more efficiently or helps minimize unnecessary inflammation (our immune system seems to be powerfully related to our gut bacteria). Or since many pathogenic bacteria are introduced to the bladder from bathroom wiping technique, probiotics can help reduce the number of pathogenic bacteria in the colon, meaning there are fewer of them around to get inadvertently introduced into the bladder that way.

I'm not sure I would describe them as "stealthy" as I would say that their optimal growing conditions seem to be pretty limited. Which is actually encouraging. Although these scientists debunk the idea that urine is sterile, the bacteria do seem few in number initially (which is partly why people thought urine was sterile) and only grow in certain conditions.

May we conclude that, since the bacteria do not grow optimally in common conditions, are few in number, and do not appear to be common wound pathogens, that using urine for hygiene applications is no worse an idea now than it was heretofore-granting that it was a moderately stupid idea in the first place, urine being HUMAN WASTE and all.

I just had to consult my bible, "Medicine for Mountaineering" by Wilkerson et al. -

"Obviously, only disinfected water is suitable for such cleansing" - p.124

I think I will follow AKSAR's wise counsel and avoid peeing into my wounds. What great things we learn on this forum....

We've covered the wound issue fairly well. What about drinking your urine in a dehydration scenario.

I always thought it was OK because I saw Bear Grylls do it on TV.