Definately, do NOT advertise them for free - besides cock fighting, dog fighters use free animals for training, to 'blood' them - then there are the BIG snake owners...don't get me started.
I had three roosters to rehome, the first I found from a posting on a bulletin board at a local feed store. The other two took a while (all were NHRs and big and gorgeous). I posted on craigslist and a local free paper for $10 each, but it was word-of-mouth that got them their new home in a nearby town with 40 hens to service. Took three weeks. Funny, I don't miss them (except to show them off, they were my gentle giants) but my wonderful neighbors do, they all liked the crowing and that "farm' feeling.