I’m not going to snarl like Ed but I’m going to agree with him. If the pages are indeed fouling up the back button’s function, then that tells me there’s a design flaw (or a conceptual flaw). I’d rethink how you’re structuring this site instead of trying to take over the back button’s functionality. Or just not worry about it; the back button takes me back through the previous pages with no problem. I don’t see a problem moving back through the history like that.
The very best way to drive users away from your site is to mess with the “back” button on their browsers. Or if not the very best it is right up there. I’m not saying that you want to drive people away from your site, but if you did, messing with the back button is about the best way to do it.
Your visitors are not stupid and if they press their “back” buttons it’s because they want to go back to the previous page, dammit! Not some other page that you see fit to impose on them.
Giving them a lnice prominent visible ink to your home page is easy to do and done all the time. Do that.