Adding power my help, it certainly won't make it worse! It may give you enough airflow over the rudder and elevators to do something.
or in the case of the Pitts S2b adding power will raise the nose , accelerate more, and flatten the spin even further. (which puts you further away again from recovery), it actually depends on the type.
I think Greeners has made the only point worth making.
Sorry guys, but if you want to learn how to do this properly, go to a suitable training organisation that will show you how.