Washing machines have been aptly described as "amusement parks for germs". (you know, just tumbling all around, no real harm). All bike clothing is marked as "Wash Cold", and most is "Hang to Dry". Use of chlorine would destroy them quickly. So, my point is, that you don't really get shorts "clean" in the wash. You just dilute the nasty stuff. It's not a matter of personal preference, it's a matter of - are you serious!!
(Please note that I've refrained from the used of all double and triple entendres, semi-obscure reference to body parts, and otherwise kept this as "clean" as I do my cycling clothing.
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