Quote - Overclocking also usually degrades CPU lifepsan, thus you have GOT to be careful with temperature and have a temperature monitoring program or feature.
I don't think it's worth the risk as I have PCs for many years, but hey, shrug

Water cooling is usually much the superior method but requires very good skills to do it yourself, though it's a hell of a lot easier than it used to be
There's some nice kits for it,  but you also need a good case to get best use, top quality cases come with fittings or features for facilitating watercooling

Nowadays overclocking is expected and processors are well protected against abuse. As long as you keep the voltage in reasonable values you won't harm processors. Mind that this doesn't apply to the other components in the computer. So be careful with your memory, your graphics adapter, your north and south bridge.

Water cooling does often create new problems with the cooling of your power regulators (which are close to the processor and are normally cooled by the processor cooling. Water cooling of your graphics adapter only makes sense if you are a big gamer. Water cooling of the other components is generally overkill. Water cooling is expensive and should only be considered when an already expensive setup needs to be pushed to the limit. The actual gains are small.