Wouldn't trust that, wet or not. Give it a day of two and it'll be full of grit.
ronnie cleans his brush 
with a power washer
Indeed I do, every Saturday morning. That wee velcro never scratches, it's the same as any brush only with much much shorter bristles, that is where it's agitating qualities come in. It's made of soft plastic and been five year's on the go on my brushes. Spring time is nearly here and all the bird poo that comes with it, that wee thing is a godsend at this time of year.