I washed my pair of Nudies around a month ago. Bought them and wore them at least 4+ days of the week all the way till mid June. I had raw Thinn Finn's, too. They were getting too small and tight so I said fuck it.
All I did was follow one of those YouTube video tutorials. Filled my bathtub with lukewarm water, laid 'em out flat, added a cup of some random laundry detergent (it's highly recommended to use Woolite Dark, I just didn't have any and didn't feel like going to the store to buy some). Massaged 'em and scrunched 'n' shit like they say in those tutorials, then let 'em sit for around 45 minutes. Afterwards I rinsed them, and hung them up to air dry.
They shrunk a bit, but the fades looked decent.
Good luck homie.