Click on Whisper Box to send your message. Type your whisper into the text box, then click on the Whisper icon. When you're in the room, click on Favorites on the Menu Bar, then select Add to Favorites. When you want to return to the room, click on Favorites, then select the name of the room you want to join. To turn it back on, repeat the procedure.
Some people are really offensive at times.
Chat actually allows you to ignore someone in a room when you are bothered by them. Select their name from the Member List to the right of the room and click the Ignore icon on the toolbar. It's the red circle with a diagonal line running through it. Whenever I'm chatting, those annoying little chat invitations and netmeeting requests keep popping up. You can change your settings so you don't receive them.