do local variables always release automatically? even the object referencies too?

[Pradeep1210]

Just pointing out that its always a good idea to clean up your object variables. Writting a few short lines of code to clean
up is not very hard or time consuming and is good insurance in case your app is resource sensitive or something.

But is this fruitful at all to do for local objects?

Does it affect the speed of our program if there are too many such objects?
Which one would be faster:
Expictly destroyed using set=nothing
or automatically destroyed by moving out of scope?