with other client...
i think you should not create persistent room with mucklů may be it even has not support of command for doing so. you should create it with pidgin or jwchat or other client. in pidgin you can change persistency and other options in window which opens if you run /configure command in chat room. also you can change them just after creation of new room. you should not create it by same user as muckl user but by user whose password is secret.