Ubuntu Manpage: CAKE - Common Applications Kept Enhanced (CAKE)
manpages.ubuntu.com
From that page:
wash
Traffic entering your diffserv domain is frequently mis-marked in transit from the
perspective of your network, and traffic exiting yours may be mis-marked from the
perspective of the transiting provider.
Apply the wash option to clear all extra diffserv (but not ECN bits), after priority
queuing has taken place.
If you are shaping inbound, and cannot trust the diffserv markings (as is the case for
Comcast Cable, among others), it is best to use a single queue "besteffort" mode with
wash.
What's the point os using wash with besteffort? Since you only have a single tin DSCP markings should matter right? I thought wash was only useful when using diffserv soo packets don't end up on the wrong tin.