Governmental bodies approved by the Department of Administration may sell any supplies owned by it after the supplies have become entirely unserviceable and can properly be classified as "junk", in accordance with procedures established by the department. All sales of unserviceable supplies by the governmental body must be made in public to the highest bidder, after advertising for fifteen days, and the funds from the sales must be credited to the account of the governmental body owning and disposing of the unserviceable supplies.