MyCleanPC and FinallyFast are SCAMS for money. Don't listen to these guys, no matter how convincing they can be, even if there's any "happy costumers", they're just paid actors!!
Use reliable software like CCleaner, avast!, MalwareBytes, Ad-Aware, etc.
P.S It's funny how software can make your internet speed 375x faster (FinallyFast claims that).