This is a pretty good plugin as far as searching your PHP database goes.
Just be aware, that just as with apps that offer to help you edit your Windows registry, this plugin, not used judiciously can do A LOT OF damage to your database.
Always be sure to create a backup before touching anything. Also, the search results I am getting contain a lot of false orphans.
As with any 3rd party tool which helps you edit the raw code of your website, with a lot of care, it can be safely used.
For me, PHP MyAdmin is a safer and better alternative, but if you don't have database administration under your belt, or if you are on a shared host without control of your server; this tool is a must have when things start to break due to remnants left behind by plugins.