Witnesses, Adventists, Age to Come/Restitution Believers, do not believe hell is symbolic. They all believe it is literal. They believe it is the grave; the word Sheol (שְׁאוֹל) encompasses the grave, especially of all the dead, a place of unconsciousness. This is within the scholarly definition of the word. Those who believe in a fiery punishment try to extend the definition to a place of consciousness. This is contrary to Biblical usage which has it the abode of all dead, righteous and unrighteous.
The New Testament uses Hades as an equivalent to Sheol. It suggests in Acts 2:26-36 that resurrection to life is out of the grave, not from a fiery hell or from heaven. This is also the thought of John 5:25-30 which has the dead, righteous and unrighteous come out of their graves.