Any ideas on how to keep it from floating to the top of the washing machine? Tried this with my daughter’s backpack (she left a 1/2 bottle of milk in it for over a month. It spilled. Was nasty.) but the padding in the backpack kept making it float to the top of the laundry machine like a life preserver. I’m going to…

Any suggestions on how to keep the backpack from floating to the top of the machine? I tried this, and the backpack floated on the top of the water the whole cycle. I tried pushing it down, squeezing like a sponge underwater to make it soak in more water, but it was too buoyant.