Hi AR, Hell, either Hades or Sheol, is nothing more than a term used for the grave, or more accurately, death. There is no consciousness in death, and hell is neither a geographical, logistical or circumscribable location.
In other words, Jesus died on the cross on the 12th hour of Friday noon, until early the following Sunday morning, and lay devoid of life in the tomb for this entire period. Jesus was clinically dead during this time, not animated or vivified, for this is the whole miraculous nature of him being raised from the dead. As for Jonah, he was not dead in the whale's belly, for he prayed to God while devoured by the whale, nor has it ever been stated that Jonah came back to life from being deceased.
As far as 1 Peter 3:19 is concerned, there is not a single person, worth mentioning, who truly understands this passage. For if Christ truly went down to the grave, and dialogued with the countless billions of souls who had died prior to him, there would not be one person who was not saved from Adam up to Christ. For, who can deny his Messiahship seeing Jesus under such circumstances (coming and going from the grave upon God's command). But, primarily, no one is conscious in the grave, they are all asleep, both the saints and the condemned.