Facebook og Meta Tags - $('meta[property="og:title"]').attr('content', 'Pasta la vista'); not working

Question

I have an AJAX website that I want to be able to post pages to Facebook, and I'm having trouble dynamically changing the og meta tags. There are a lot of Stack Overflow threads concerning this, typically with the same answer:

$('meta[property="og:title"]').attr('content', 'Pasta la vista');

I have not been able to get this to work. I've tried a number of variants that were suggested in other threads, including:

    $('meta[property=og:title]).attr('content', 'Pasta la vista'); 
    // no quotes around og:title

    $('meta[property='og\\:title']').attr('content', 'Pasta la vista'); 
    // adding the "\\" after og and before the colon

    $('meta[name='og\\:title']').attr('content', 'Pasta la vista'); 
    // changing "property" to "name". Someone suggested this was a Chrome issue

    $('meta[property='og\\:title']').attr('content', var); 
    // instead passing a variable as the second argument rather than a string

It seems that others have had some success with this, but I can't seem to figure it out. I've tried both passing these off to the Facebook Debugger as well as checking the page source output through the browser, with no results.

UPDATE The only thing I can think to do instead is to create proxy html files that basically just contain these og meta tags, and that execute javascript that redirects to the correct hash URL. Then, maybe use HTML5 pushState somehow to put this vanity URL in the address bar again, just in case the user wants to share the link on Facebook.

As far as I can tell, the only way I can get different og meta tag information into Facebook Debugger is with an entirely separate HTML file.