Laundry Soap bar
Bar soaps are cost effective. You can buy many bar soaps in just the equal amount that you need to buy only one bottle of liquid soap. Bar soaps prevent wastage. It is easier to know the exact amount of soap required for washing when using bar soap than when you use liquid soap.
Since it's a solid bar you won't have to worry about getting through airport security and laundry bar soap works well as a stain remover when you're at home.