I've noticed that some people have macros (like super mario) and others that start the line with /r or /g, /say, whatever, just to send to one channel. If you leave off that initial command, it will be sent through the last channel used. I frequently have the Kirby buttsex, the kriby bitchslap, and the monster face up through either guild/raid/general or otherwise all by utilizing the same macro (without editing) just by switching the currently used channel.