Hades is Not Gehenna `

 There's a difference between Hades and Gehenna.  I always thought they were the same.  It's the difference between hell and purgatory.  Hades is a place you can't come back from 

Gehenna is the name of the valley of the "sons of Hinnom," which is a place people sacrificed to Baal.  The sacrifice was often people but more often garbage was thrown there.  It was a dreadful place.  The gases piled up in this dump and sometime combusted into tiny fires. Maybe the Gospels mentioning everlasting fire were thinking of the smoldering refuse in Gehenna.

Am I wrong in thinking that when Jesus descended to the dead, in the Apostle's Creed, He went down to get those people in Gehenna?