CCleaner, no. Every once in a long while can be useful, but it's debatable.
Defrag, yeah, defragging is generally a good idea. Once per month is enough though. I suggest PuranDefrag
, as it is a pretty handy utility to do that (as it does also optionally "optimize" the system by moving most system files in the faster areas of the hard drive, I usually untick the "leave free space for temporary files").
Don't expect major performance improvements anyway.