This script will hide AO3 work blurbs that contain one or more of the words or phrases you specify. The blacklisted terms can appear anywhere in a blurb: title, author, tags, summary...
The script is currently set to hide work blurbs that contain the terms "explicit" or "mature." You can remove these terms and add as many as you like by editing the part of the script that reads var blackList = new Array('explicit', 'mature');
You can whitelist terms as well. This will show blurbs containing the specified terms even if the blurbs also contain a blacklisted term. That can be changed in the the part that reads var whiteList = new Array('general audiences'); If there are no terms you want whitelisted, use var whiteList = new Array();
Updated to Version 1.4 on 8 October 2013.