This isn't a windows machine, try and get out of the habit of trying to "clean" it as one.
OS X doesn't gunk itself up over time like windows does. It has no registry to mess up, isn't prone to malware, and the file system even defrags itself as you go. Heck, the size of the OS won't inflate by gigabytes due to updates like windows does either!
Use your computer, and leave it at that, stop trying to fix something that isn't broken.
I use CleanApp which helps when I decide I don't want to use an app and just want it all off my computer. However, the more I use CleanApp, the more I realize the same can be done with a spotlight search for the app name you're removing. I think deleting anything more than a related folder in the Library or a .plist file is asking for trouble down the road.