It's the flooding problem most of all. I'm in one of the few Manhattan co-ops that still allows washing machines and dryers and it's a wonderful thing to have it in my apartment. But many landlords, co-op board and condos don't permit them because of the flooding.
Sodium acetate or hot ice is an amazing chemical you can prepare yourself from baking soda and vinegar. You can cool a solution of sodium acetate below its melting point and then cause the liquid to crystallize. The crystallization is an exothermic process, so the resulting ice is hot. Solidification occurs so quickly you can form sculptures as you pour the hot ice.
The more ice cream that is in immediate contact with air, the faster it will melt. A lower surface area to volume ratio speeds melting because the air can share its heat energy with more of the ice cream at one time. Imagine how much easier it is to for an ice cream flake to melt than a ball of ice cream. For the ice cream to completely melt, the air has to share its heat energy with the ice cream on the surface and the ice cream on the surface has to share its heat energy with the ice cream in the interior of the flake or ball.