Complex sentence: In contrast, "dessicating toilets" dry the excreta to destroy pathogens, though one study suggested that drying can result in rehydration of pathogens when in contact with moisture later.
Split into simpler sentences: In contrast, "dessicating toilets" "dry" the excreta to destroy pathogens. However, one study suggests that drying can result in rehydration of pathogens when in contact with moisture later.