If they'd done the smart thing and voted out the recipient of their idols in advance, they would haveI also think whoever went on that journey was going to fail - if Christian couldn't do it in time I doubt anyone else left in the game could have either. Kamilla might have - she seemed good at puzzles?
But really finding the Billie Eilish Idol and then not being able to keep it was such a screwed up concept in this season with all these twists. Both Genevieve and Christian should have had the opportunity to save themselves with idols they found.