I think Malcolm was right to use both idols. Chances are quite good that he'll find at least one of them again...and probably the following day. TPTB seem to want the idols to be found, and Malcolm appears to be one of the few who will spend enough time looking to actually find them. I say use them when you've got them, and then spend the next day finding them again. One in the alliance of seven commented that they don't know why they spend so much time sitting around camp, instead of out hunting for the idol. (Dawn maybe?) Anyways, the seven were so confident they apparently didn't see a need....until last minute when they watched Malcolm find it while they were standing around.