I dont think it works just by adding few lines of code, or is it?? at least, if that is the case, wouldnt the core dev team already include it in the core long time ago?
As Mambosolition said you need <embed> and <object> tags for it
I've also tried it using a full html code from a static html to the editor and it still not working. The only time i've been successful adding flash to content is by using and Iframe.
and as a note the request for adding Flash into content is already asked from many people from the time of mambo 3.0.x
Is it a matter of commercial product vs GNU/GPL?