(cent 1:) long story short: only, if necessary, better keep it clean in first place
(cent 2:) long story (which is the essence of what you also find elsewhere on the net):
better to take care of your ropes that you never get to the point of this decision, of course
there's already 'studies' that proof that ropes age and break faster, when being dirty
maybe still prefer handwash (e.g. in a bathing tube) over machine wash (you should only use the handwash-program anyway)
if you do that more often, get a rope brush, makes it easier/faster
let a washing program run (with only some old clothes or shreds in it) without adding any detergent--so that the washing turn cleans out rests of settled detergents in the machine (there is still a lot of! you'll still have foam in the machine without adding detergent!)
use a soft program, without skidding in the end
only use very mild detergent, in best case one for similar textiles, you can even get rope cleaners
crucial part: drying. not in the sun, not hanging, on a clean, shady, well vented surface, for days(!), maybe revert from time to time that there are no hidden wet spots
back into it's rope bag and back to step one: take care of it! ;-)
Mark M started this discussion 5 weeks ago.
Rope and wasching machine
What are your thoughts on putting a dirty rope in the washing machine?