You can use fabric softener, very diluted, on the rope before drying.
The softener acts as a lubricant and helps to resist soiling.
There is some evidence that fabric softener can help
for nylon, & maybe other, ropes. "very"* might here also
be unwanted, but Knotrigger might have among his
Nylon Highway caving newsletters some that show first
a charge (by Bruce Smith, IIRC) that fabric softener is bad
for ropes, then a defence by CMC's James Frank that it is
not --if used appropriately, and not w/o proper dilution.
*(I object to "very" on behalf of so many adjectives that
do NOT want it, as it dilutes their already adequate meaning!)
Using a washing machine might show value in both
agitating away dirt and especially spinning out water,
to speed drying. (I tend to hand-wash woolens but
coincident w/some machine wash so that I can toss
the woolens --socks, mostly-- into the spin cycle to
help (hang) dry.)
Incidentally, bleach, hardly a mild chemical to be used
carelessly, is said to be okay for nylon ropes if diluted,
adequate for sanitizing. (For nylon, water alone is a
more severe strength reducer, but whose effects vanish
along with the moisture --reversible, i.e..)
--dl*
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