There are people who don't wash everything, every time?
FFS, are you serious? Wash your stuff - ALL your stuff - every damn time!
I wash everything - shorts, jersey, socks, gloves, and anything else I wore (warmers, jacket, skullcap) - every single time I ride, no matter how far. I use the machine on cold/gentle, then hang to dry (quick, cheap, environmental, stuff lasts longer).
Otherwise you are just soaking your gear with sweat, snot, skid marks, cock drips, foot odor, etc., then letting it all fester. It makes you stink, and can give you sores, rashes, infections, and other nasty skin conditions. It is also plain disgusting.
Really, not washing your stuff every time is just skanky.
/rant