what about instead of squeezing the sponge you vigorously shake it under the water, the idea being that you move more water through it than normal, forcing the bubbles out of it, i have never kept sponge in my tank so i don't know anything about it, but i have been following the thread, maybe it will work maybe not. also if you think about a cup, if you turn the cup upside down under water it holds air in it, but if you turn it right side up then the air escapes and is replaced with water, by shaking it and turning it, it ay be possible to make the air be expelled, maybe saving the sponge from any tissue recession or death