IMHO the best cleaner out there is CCleaner.
http://www.piriform.com They are Microsoft certified........been around a LONG time.
You can pay for the scheduler version or use the FREE.
I use the FREE and various times during the day I'll right click on Recycle Bin & run CCleaner instead of just "empty recycle bin".
It takes just a few minutes and since a lot of viruses hide in temp folder this ALSO helps out there too.
My "defense" on PCs is Avast 8 (hope to upgrade to v9 when stable), MBAM PRO (no conflict with Avast), CryptoPrevent and CCleaner.
This combo keeps me well armed against most things....and also good habits of not going or downloading what I should not.
The problem with new software like Grimefighter or others is that they cause more problems than fix.
Plus, the problems they can cause because of the nature of what they do can BRICK a PC.
I would never run a reg cleaner from any 3rd party but if you must use CCleaner's....it does good job and does not jeopardize your PC.