Using a switch port as a separate dev/interface

I'm wanting to create a mirror port off the RT-AC68U. I could use an iptables tee but I was hoping to do it another way. What I'm thinking is to use the traffic control subsystem (tc) and create some filters to do the mirroring. But from what I can tell, I need an interface to mirror to. So how do I use one of the switch ports? Somehow remove one of the ports from the switch and get it recognized as its own device/interface? Has anyone tried this?

I see some promising things in the...

Using a switch port as a separate dev/interface