How does flicker relate to a card like Ulamog's dispoiler
You can't cast or resolve anything whilst the target of Flicker is in exile, as it is returned to the battlefield as part of the spell.
You could do it to the target of Otherworldly Journey, as that returns the card at the next end step. If you did, it would stay in the graveyard, the object in the exile zone that Journey is looking for is no more.