Screw-on caps r a must, as reommended for toothpaste. I substitute bodywash for shampoo and laundry detergent. Problem is u won’t find bodywash in travel size OR with screw-on caps so I use an emptied out Pert shampoo traveler refilled with body wash. They have a screw-on cap. I know camp soap is recommended but it’s absolutely worthless so why even subject THAT schitt to the environment?