A bleach helps get any dead organics off.
A muriatic acid bath gets an outer layer of rock off, theoretically getting rid of any absorbed phosphates, but will remove some rock.
An acid bath immediately after a bleach treatment generates chlorine gas which additionally kills any other animals, including humans, who breath it.
A soaking in saltwater, even room temperature, lets bacteria do the dissolving of organics, and removes the need for a cycle in tank.
The complete treatment then is:
* Bleach soak, with power head
* Major rinse, possibly redry, dump all water and refill
* Run through muriatic acid, outside, in a ventilated area that is not going to blow into houses
* Baking soda tossed in the water to neutralize the acid
* Dump, rinse
* Saltwater cook with your choice of bacteria sources and/or pods & phyto to get it full of life
Skip steps based on how willing you are to mess with it, and your goals.