Remove brainwashing

"As long as this card remains face-up on the field, the control of all monsters on the field returns to the original owners."

If this card were to be destroyed, would all the monster affected by this switch back to the player who originally controlled it?

With example of Lava golem. If I used this card to gain control of my lava golem on my opponent's side of the field and then this card was destroyed afterwards, would Lava golem's control switch back to my opponent or would it stay on my side of the field?

No. They stay where they are.

Thanks. I've dueled a few players who claimed that the monsters affected by remove brainwashing switched control if the card was destroyed, so I was unsure of this.