Do you think buying an external fan set for the PS3 helps to make it cooler?
There are different types, which blows the cold air from the side, or from the front, and it doesn't cost much, but I dunno if it's really worth it.
No not worth, design is faulty by itself, best way is to replace for good compound under IHS and over it on CPU/GPU and hope for the best as problem is in lead free soldering points
I have bought external fans for PS3 on slim, but from what I know they block inner airflow more than they help.. I would suggest as above even on some slims.