If you're a capable user, most things come and go as normal as can be. If after some time, things start to slow down, maybe just MAYBE they could come in handy. I have used CCleaner for some time and being free is a plus, though you can support $ to it. What it does as other helper pgms. do if just fine now and then. They aren't meant to be used in extensive daily or general use too much, though it shouldn't hurt if everything is going well. What happens are that users tend to play too much with them or use advanced setting and may enter areas best left alone or they error in its use. That being said, the ones you mentioned are quite good and work well in default modes.
My typical use of CCleaner are slow but yet bootable PCs that for all intents and pusposes are working. In some cases, the user hasn't done anything to help make the PC go-go but has noticed a slow down. i run the MS supplied disk cleaner and then ask if any s/w can be deleted or removed as in no longer used or found to be too old or redundant. Redundant are usually toolbars and possible old games not played any more, etc., just asking the user if not needed, thus removed or deleted. Next, i run CCleaner and after a successful run, using cleaner and then registry buttons, reboot and defrag the HD. Usually, there is some improvement in speed and access times. Other than the time spend doing all this, it's a rather painless operation.
tada ------Willy 