Abstract: In a bottle cleaning operation, bottles to be cleaned are introduced into a machine housing divided into a first housing and a separate second housing intercommunicating with one another through a bottle transfer section. Bottles are introduced into carrier compartments mounted on a first endless circulating chain in the first housing. After undergoing certain cleaning procedures in the first housing, the bottles are transferred into the second housing with the bottles passing in a free-falling manner from the first circulating chain. Within the second housing the cleaning operation is continued with the bottles held in carrier compartments on a second endless circulating chain. After being treated within the second housing, the bottles free-fall from the second circulating chain and return into the first housing for completing the cleaning operation before the bottles are discharged from the first housing.