Yes, this ^^^^.

I recently discovered a test in some old geological text that can tell you right off the bat whether your Washita is on the coarser or finer end of the Washita grit spectrum. Water absorption.

You need to get the stone free of at least most of the oil to let the test work OK. I use Simple Green soak in a heated ultrasonic cleaner... works great. You'll need a decent scale to measure the weight. First, let the stone dry out after lapping/oil removal until the weight stabilizes. Record that as the dry weight. Then soak the stone in a tub of water until it stops gaining weight. Record that as the wet weight. (Note that with some stones this may take days). Divide wet weight by dry weight to get percentage weight change.

The stones at the finer end of the Washita spectrum will absorb enough water to change the stone weight by a percentage on the order of 0.1% and the coarsest will change the weight by an amount on the order of 6% - 7%.

I have two Washitas, one of mine is right at 0.1% - 0.2% and the other is at about 1%.