where to put Disqus or Intense Debate embed code?

I'd like to try using Disqus on my Omeka site but am not quite sure where to put the embed code. I want Disqus comments to appear at the bottom of item pages - and ideally, I'd like to be able to control whether Disqus comments appear based on specific item attributes - though I'll happily settle for just my first ask at this time :)

It seems from a now 3-year-old forum discussion on Intense Debate (http://omeka.org/forums/topic/intense-debate-comments-plugin) that the best place for the embed code would be in themes/default/items/show.php but I haven't had much luck with this. Perhaps this is related to "plugin_append_to_items_show()" no longer being in the show.php file?

I'm using Omeka 2.2.2 by the way.

Thanks in advance for any insight or assistance provided.

I use Disqus + Omeka 2.3.1, put the embed code in my_theme_folder/common/footer.php and it shows on every page. BUT I do want Disqus showing on items/show/xyz pages only. How to do this? Hints are appreciated. If this is an issue too hard to solve, a quick reply also helps a lot. Thanks.