When cleaning Mac / Lion files using Mac keeper, Are These Files Safe to Clean? Some of files are cashes, temp, duplicate plus the others. Certainly I would do a backup 1st, but in all, is a quick scan safe?
Try not to continue to be sucked in by the hype that is associated with MacKeeper.
There is almost nothing that it provides (for a price) that is not available for free from other sources.
And, you get to decide to listen to the experts here, who mostly will tell you that OS X is actually pretty good at maintaining itself in most uses. Most third-party "wonder" utilities have very limited real need. Actually paying for that function is just your own fault.
MacKeeper is likely the worst of the lot (and not the miracle worker from its own advertising.) Even worse, is that you have to pay good money for MacKeeper!
Sure - if you can't afford enough space. You still pay a good premium to get a lot of space on an SSD. In my experience, the files that you mention don't usually take up a significant amount of space, and you may get up to 5 GB from that process (assuming that your Mac system is functioning properly), but not every time that you clean. If that small amount makes a big difference for you, then you need to consider external storage, in addition to your internal boot drive.