> What did the rock do? Possibly the same trick that the Foreign Legion used in the Sahara; a small stone held in the cheek tricks the mouth into generating m

> What did the rock do? Possibly the same trick that the Foreign Legion used in the Sahara; a small stone held in the cheek tricks the mouth into generating more salivia, reducing the perceived 'thirst'. The underlying hydration isn't addressed but it does psychologically increase endurance between drinking.