Initially, I was cleaning my brushes after 5 or 6 uses....but now much less often. Interestingly enough, I have actually noticed increased performance out of my SR 3124 without washing it for over a month. Also note, that I have been consistently using preshave oil as well (which most say affects water retention - I disagree!) The brush actually feels heavier in the hand now, and holds more water than ever. All hair has natural oils contained, and I wonder if cleaning the brush too frequently strips the oils from the badger hairs and subsequently dries them out. Any thoughts?