Originally Posted by
Russel Baldridge
You are correct, there are various sources (such as John Juranitch, authority on blade sharpening for the meat packing industry) that have done extensive tests and find consistently that slurries abrade much more rapidly and aggressively than plain stones, which leaves the edge more ragged and unrefined. Juranitch even advocates using stones dry, as any lubrication allows the grit particle to build up to some degree.
Then again, I use a slurry made with a diamond hone, because naguras and cotiguras to me don't make sense, why would you put abrasive form one stone onto another of possibly differing grit size (like using a cotigura on a 12k, what you are doing is mixing the abrasives, and lowering the results of which ever is the finer stone). So with a diamond hone you are using the stone's own grit to cut faster, and not contaminating it.
I always finish with no slurry (and minimal water) so that the edge is as fine as possible, but the steps leading up to the final polish I use a slurry to speed the process up.