Filter rows by CSS selector

Example fiddle: http://live.datatables.net/gamuxure/1/edit

I'm using documentTable.rows('selector-string') to grab rows matching a CSS selector, then attempting to filter the table by chaining .draw() on that.

That appears to not be the right thing, as the table doesn't appear to change. No errors in the console, unfortunately. I'm tasked with fixing up one page on an existing site, so I'm afraid I don't fully understand the DataTables API even after browsing the docs.