To me, a slurry is dependent upon what you are doing and how you are doing it.
Heavy slurries are for setting bevels and repair work. Just because we see tons of awesome slurry on hones to show what they yield does not mean it is always practical to use, FME. Some slurries are to make cutting fast while some are quite light to 'Fill' the hone and make it cut finer. I do think all should be thinned to nonexistent as-used. Some like to leave the broken-down slurry on the hone for next time. Sounds interesting!
Anyway, I think as honing comes to a point (discovered by idiots like myself), pushing mud does not a sharp razor make! Hence, 'slurry dulling' .....JMHO