You should clean your kegg device both before and after your daily reading. You need only to rinse it with warm water. You can use soap if you want, but kegg recommends using a "neutral" soap if you do (i.e., something you'd use on sensitive skin). Don't worry about frying the electronics, as kegg is water-resistant (though you shouldn't be dunking or soaking it). After cleaning, use a soft, clean towel to dry the kegg device. Be gentle because you don't want to scratch the gold-plated electrodes and risk inaccurate readings as a result. As for storage, the best place to keep the kegg device is docked in its charging base. The base has to be near an electrical source, but keep it away from any place where it can be easily knocked over.