I know I use to reuse them too, then we had a customers car seize the oil pump, the visable part of the pickup looked spotless, the oil pump drive looked like a pretzel.. The bearings were wiped & the crank had to be turned... Cut the pickup screen apart & it was full of debris... New screen for that job was around $7.00..... Since then I don't take a chance, but I often throw the screen in with the parts going to the hot tank & I'll cut it open after tanking to see how clean it really got.... I haven't ever thought gee, I shoulda saved the cost of a new screen...