Here's what I do when my fly lines get a bit tangled. (Do this on Grass)
Firstly attach a reel & line to a rod butt & thread the line through the rings. Now attach a braided loop if your line doesn't have one & fix it into the grass with a scewer or similar & walk the line off the reel until the backing knot is exposed & detatch the line from the backing. Now I use a cleaning pad & run it along the line from the tethered end back. Beacause the line's fixed to the ground through the scewer, all the twisted are transmitted up the line & off the free end. Now give it a REALLY good stretch & leave it for at least 10 minutes before re-attaching to the backing & winding back on the reel.
I usually do this about every 10 times I use a line & it really helps to reduce line kinking quite a bit & seems to extend the useful life of the line.
hope this helps mate
JC