How to entirely uninstall MacBooster

Oops. So I went to the DivX site to make sure I got a legit copy (before remembering that I no longer need DivX) and installed it. It mentioned MacBooster and I thought, "well, I'll install it, and then do some research..." Oh, I really shouldn't install stuff at the end of the day.

Okay, I'm an idiot. But now what?

I used finder to locate and delete the MacBooster app and a folder it was using for data. When I did that, something called UninstallMonitor wanted me to type in my password. I canceled out of that, because I'd never seen that before. Those files did get deleted.

Every time I delete a folder, UninstallMonitor prompts me. I cancel, and the delete happens as expected. I found the little bugger in the Activity Monitor. And it appears in launchd as com.apple.UninstallMonitor. Cannot find any reference to that on the interwebs, so I'm planning to remove it from launchd config. "UninstallMonitor" is apparently part of MacBooster.

Then today the Big Blue B (MacBooster's logo) appears on a dialog telling me that my trash is very full and I should delete it by pressing okay. I hit cancel, because I have no idea how to otherwise kill a dialog. I can empty my own trash, thank you very much.

1. Do I need to reinstall the OS to rid myself of DivX, MacBooster, UninstallMonitor, and any other horrid crap installed by the new DivX Dark Side?

2. Or am I close to recovering manually? What steps do I need to take? Incidentally, MacBooster claims to have a full uninstall feature. I would assume that's like asking the fox to monitor the henhouse.

3. Or will upgrading to El Cap take care of this? If this is the answer, please be clear. Some would have me upgrade first "just because" which is not quite what I'm looking for. I want to rid the Earth of MacBooster, and give all its assets to orphans. Or, at the very least, get it off my laptop.

Help me recover from my moment of weakness! Thanks.