I have had them sent to me that way but I've had better luck with receiving live snails when they were shipped "dry" wrapped in moist towels. I've also had them shipped with wet moss to help keep moisture but yes, you sure can ship them in water and together. But, if your gonna send the tub anyway, I'd skip the bag and water. just use wet towels and tape the tub shut. Wrap each individual and pack them together. Wish I had pics of the process to send you. Snails ship pretty well. I've gotten my sw snails shipped in a shipping bag but without water as well.