If you don't want to buy specific cleaner for it, you can do this (I have done it many a time and it works like pro):
-Warm Water
-Liquid dish soap (like Dawn) DO NOT USE THE POWDER DETERGENT FOR DISHWASHERS OR LIQUID HAND SOAP
-2 Buckets
-2 Clean Washcloths
-1 large clean towel
1.) Fill both buckets with warm water. You don't want scalding/hot water or cold water. The warm water will help the plasticizers do their job better. It will loosen the fly line making it easier to clean.
2.) In one bucket, squirt some of the liquid dish soap, mix it around so that it dissolves into the water thoroughly. Squirt a sufficient amount but don't under or over do it. I can't tell you exactly how much to put in because it isn't an exact science. Just eyeball it and when you think you have enough, you should be good. Remember, a little liquid dish soap goes a long way!
3.) Take your fly line and place it in the bucket that has the soap. Completely submerge the fly line in the warm soapy water. Take caution not to tangle the line, it makes things difficult.
4.) Take one of the wash cloths and soak it in the soapy water. Ring it out but make sure it is still a little damp and soapy/sudsy.
5.) Proceed to take one end of your fly line, place it on the soapy moist wash cloth. Grip/pinch the fly line with the soapy wash cloth and proceed to pull the line through the wash cloth. Make sure you apply sufficient pressure to the wash cloth that you have to pull the fly line through it with some force but not too much where you are pulling excessively. You want the friction of the wash cloth and the fly line to pull the dirt off of the fly line with the help of the soap in the wash cloth. Pull at a constant rate/speed and at a constant force. Make sure each pull is a constant length too. I usually go about half an arm's length and then start a new pull.
6.) As you pull it through the wash cloth, feed the end coming out of the wash cloth into the second bucket of warm but not soapy water. Every 5 - 10 pulls, change the part on the wash cloth that the fly line is being pulled across to ensure that you aren't redistributing the dirt that already came off, back onto the fly line.
7.) Once you have all the fly line through the soapy wash cloth and into the warm but not soapy water/bucket, swish around the fly line in the non-soapy water, taking care not to tangle the line.
8.) Take your 2nd wash cloth and do the same as above, with the exception of: don't wet the 2nd wash cloth and once the fly line comes out of the 2nd wash cloth, as you pull it out, feed it on to the clean large towel. This should help dry it and keep it clean.
9.) Now that your line is clean, you just need to reel it back onto the spool and you should be good to go.
When I do this, it usually takes me about 45 - 60 mins from start to finish.
Good luck man!
-Spydey
