Each logger object has several methods that you can use in order to interact with the logger's appenders. You can add, remove, clear or list the appenders on a specific logger instance. Below are the methods you can use in the logger class to interact with appenders:
So you can easily add/remove/check the appenders on any logger at any time.
//Add your own appender at runtime
jms = createObject( "component", "com.appender.JMSAppender" ).init( "JMSAppender", properties );
logger.addAppender( jms );
//log a message to all appenders and to my jms appender:
logger.fatal( "I FAILED MAN!" );
logger.removeAppender( "JMSAppender" );