Indeed baryogenesis is one example of baryon number violation, another is Hawking radiation - baryons forming stars and finally ending as massless radiation.

In both these examples conditions are completely extreme - what might be the missing factor for human attempts to directly observe it: in room temperature water.

I would rather expect it e.g. in the centers of some neutron stars - especially those thousands times brighter than possible with standard explanations, like: https://www.space.com/bizare-object-10-times-brighter-than-s...

While electric charge is ultimately conserved due to Gauss law, there is no Gauss law for baryon number.