In an attempt to loosen the shape of the last dregs of filament on a tightly-wound roll, I unwound the last (15 or so percent) of it and took it off the spool completely. Then, keeping track of the ends so they wouldn't tangle, I manually counter-wound the filament such as to reverse it's tightly-wound shape. The filament fought back a bit, but when I got it to a larger overall size (or into a looser bunch), I tied the ends and the filament to the coil with zip ties to reinforce the new, looser and desired shape.
Now, I'm putting it in the sun for several hours (~70-80 degree F w