I've used just about everything to clean my fly lines. The worst luck I've had is with the SA cleaning pads. Basically, those just grind the dirt into the fly line and tear off the finish. Cleaners seem to work ok, like glide and armor all, but they don't seem to get the line clean. The best by far for me is mild soap and warm water and a soft rag. It gets as much or more dirt off as any other method without grinding it into the plastic coating. After washing I rinse the line really well 3 or 4 times, filling a sink w/ clean water and draining. The thing about soap is if you don't get it all off it will attract dirt worse than the line itself. Once the line is clean I let it dry for an hour or so then apply Russ Peak's or SA or glide dressing and wipe off the excess. I find that if I'm religious about doing this every time or two I go fishing the line lasts about 50% longer than it would if I used any other method of care.
I encourage you to try different methods to see what works best for you. It may be that the conditions you fish under are different than mine and you may find another method works better.