While doing a redesign of two sites I had this need to take my clients TemplateMonster template and show flash on ONLY the front page and a static image on the internal pages but the problem was that it ran on a template engine which used a single load header type setup not to different from a wordpress template. That being said, I simply added some php to show only the flash file on the home page.
Now this DOES work for WordPress, Open-Realty, vBulletin and many other theme engines I've designed for over the years.
Here is the basic idea.
If the home page, show the flash, if not show something else.
File: flash-slideshow.php would include the flash code as well as the JS link to the swfobject fix for flash and IE.