Hi, I'm not a tekky, I run the whole gambit once a month..even verifying, at one time it showed I had an issue, I repaired the issue & have every confidence in OnyX. Cache's & Cookies can be cleaned out as they refill themselves as you open websites etc. I'm sure George Peters can give you the tekky side of the discussion, but for me it works & I'm happy. All my Macs are on 24/7 as I run a Security Spy -a video surveillance system...L