I go to Columbia a lot for work (I'll be there tomorrow for example). Live in Greenville, and my experience with the Cocks Fans has been pretty good thus far. I remember the day after they won the Baseball NC, I went to dinner at an Outback there. While I was eating, one of the servers came out wearing some ridiculous looking rooster (like a plush toy) on his head. I looked at the bartender and just commented that, "Columbia, SC is probably the only place in the country you can walk into an Outback, sit down to eat and be totally cool with some dude walking around with a huge cock on his head." He got a kick out of it. Gave me a War Eagle when I walked out the door and everything.
Agree with the rest here, I'd still go neutral or very subtle.