In case anyone is wondering I can confirm, after extensive testing this morning, that it is indeed possible to wash your hands-free headset at 40 degrees, with an extra spin cycle, and it will still work. 
What brand of washing power did you use and did you iron it afterwards
Has the fabric conditioner make it all soft and fluffy for your ear 
It depends on the make and model. The old curvey Motorola 3 button ones don’t like it. Some of the Sony thin flat ones survive after being rained on but not for long 
Congrats! Just wait a few days and remember to report back 
Bold washing gel, Comfort fabric softener on a 40 degree wash and it is still working fine a couple of weeks later. It was just a headphone type one, two ear-buds and a button built into the wire you can use to answer it, and not one of those Bluetooth things make you look like a ■■■■.