The idea is simple. As I described earlier. Every invention or innovation can be reduced to a name. Presented with a name of an invention could then be enough for your imagination to work on.
Bathing Sponge → Water Sponge → Fluid Sponge → Gas Sponge
Now that you have guessed the name of the invention. You will try to figure out what a gas sponge could be. What could it be used for? What does it do, what does it look like and so on. From my primitive Google search there exist cement that stores some amount of gas. Maybe this sponge could suck up a particular gas from the air.