A question asked, an answer given..
Familiar-Object-4237 asked what would happen if you tried to sling a water balloon.
I made 3 different sizes: big green, medium pink, and small orange. Heres the results:
-Big green- blew up the moment I tried to throw it.
-Medium pink- can be thrown, but deforms so much when you throw it that its pretty much impossible to aim without throwing super slow (and if you throw slow whats the point?)
-Small orange- deforms like pink, but to a lesser degree (duh). Maybe if you were a slinging genius, and adjusted your throw a lot, you might get it going in some direction that could be considered straight.
-BONUS sponge- surprisingly passable. It sprays water like a sprinkler as you swing it, but if you throw before you swing it too much, you can get it to go mostly straight while still having enough water to get someone a little bit wet.