The
CRB is a marvelous tool for scrubbing out the grooves and grain, but make sure you use a gentle brush and only as much pressure as you need. The recovery can be with a hard floor tool, or (if you don't have one) a simple spin mop.
We use a neutral cleaner or a non-ammoniated glass cleaner, "Zep" concentrate from Home Pisspot.
The sludge has to be seen to be believed. Of course you can add necessary odor killers, disinfectants or whatever the floor needs, to augment the detergent.
For us, it is part of a good deep clean when Mrs. Custy wants all the old cooties moved out before they move in.