When a fly line gets really dirty, the microscopic pores start to fill with muck, and simply wiping the line down with a wet cloth won't do the job. Rio's (www.rioproducts.com) Wonder Cloth is a very fine, abrasive fly-line cleaning pad. The superfine abrasives strip out deep-lying dirt without roughing up the fly-line coating. Just fold the pad around the fly line and pull the line through a couple of times. Each time the line is pulled through the pad, a layer of pore-deep dirt is stripped off. The unique material can be thrown into a washing machine with whites and washed for reuse. The Wonder Cloth is sold in packs of four and is available from all authorized RIO dealers for $4.95.