Perhaps the idea that Christ went to hell is taken from the following verse where it states that he preached unto the spirits in prison
1 Peter 3:18-20
18 For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
19 By which also
he went and preached unto the spirits in prison;
20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
During the time that Christ's body lay in the tomb, his spirit went to those who are in the world of spirits awaiting the resurrection. A revelation given to the prophet Joseph Fielding Smith reveals where exactly Christ went from the time he was crucified until the time of his resurrection.
Doctrine and Covenants 138
Jesus went among the spirits of the dead and organized the righteous dead to go among those who were wicked in this life and those who never had a chance to hear the gospel and preach to those in spirit prison. Until the day of resurrection the disembodied spirits of the dead have a chance to still receive and accept the gospel. As a spirit, they are not able to have baptism and other ordinances performed on them personally. For this reason the ordinances performed in the temples of God by the living for the dead are performed, baptism for the dead being one of those ordinances. The Apostle Paul understood this principle and for this reason taught regarding baptism for the dead.
1 Corinthians 15:29
29 Else what shall they do which are
baptized for the dead, if the dead
rise not at all? why are they then baptized for the
dead?
In all his fairness, the Lord will give all mankind a chance to receive and accept his gospel before they stand before him in judgment.