How to get the washing sponge?

The washing sponge is the third item in the cleaning supplies line. You need to merge rags to get the basin, then merge the basins to get a washing sponge.

You get these items from the cabinet for cleaning supplies. And to get the cleaning supplies cabinet, you need to start off with a single small wheel, it looks like the wheel of an office chair, then keep merging until you get the cabinet and it starts to be able to give you things.