I had a half hour soak in a bath with sulphur lyme dip in it and the entire bottom of the bath was covered in black specks. I have sent the specks off to Entomologists and they said they could not see mites. I think the black specks are their poop. I know their eggs are white and pearlised and hard like a grain of sand.
I have bird mites or canine sarcoptes. More likely bird mites.
Best to check out ICU protocol for dosing. I am bad at maths too. Would hate to give you the wrong measurement.