Put this in ~/Library/Application Support/Propane/unsupported/caveatPatchor.js

caveatPatchor.js

function sayIt(msg) {
  message = this.chat.transcript.insertPendingMessage(msg);
  new Campfire.OutgoingMessage(this.chat, message, msg, '').send();
  this.chat.dispatch('messageSpoken', message);
}

Campfire.Speaker.Filters.push(
  function(message) {
    if(message.match(/^\/soundlist\s*$/)) {
      var soundList = [];
      for (s in this.chat.sounds) { soundList.push(String(s)); }
      sayIt('Yo dawg, the current sound list is: ' + soundList.sort().join(', '));
    } else {
      return message;
    }
});