I have 360 total security as antivirus and glary utilities for cleaning it. usually, since I use Common sense internet security 2015 (as stated on a sticky thread), I dont really worry about putting my antivirus to make a full scan unless I think that I am infected with something.
in case of glary utilities, I dont really have like, days to run a scan. when I see my computer starts to run with low speed or somenthing, I run a scan, and sometimes I find a good 10GB cleaning hahaha. but I would reccomend running a system cleaner (being glary, ccleaner or even diskcleanup (from microsoft)) once a month. ofc, it depends on what you do on your computer.