[poulsbohemian]

I'm very confused how you make a watertight box with a sheet of standard printer paper - would seem like either it would very quickly be a wet mess, or you'd have to fold it so many times to have any durability that it would be too small to contain a meaningful amount of water.

[defrost]

Back in our school days, well before personal phones and all that, we'd often make folded paper water bombs,

eg: https://www.google.com/search?q=origami+water+bomb

returns maker videos, text instructions, etc.

[dineol]

paper water bombs worked very well!