The way I do it is by keybinding how they chat. For example: My Main toon uses the default chat commands i.e Enter & /. On my clones I have it set up where the left one enters chat by pressing "Ctrl & Enter" and my right one by pressing "Alt & Enter." The "/" command is unbound on the clones as well. So, buy pressing "Ctrl, Alt, Enter" I get all 3 of my toons to open their chat command at the same time and thus able to say "/hi" with all 3.

Macro's just make it easier if the emote requires a target, because you can build the Main Toons target into the macro. Unless you already have a stand alone macro like:
/target [target=focustarget]