I am also in a similar scenario of having to clean the fountain fairly regularly. 100pcs/$12 looks to be a deal. I checked out amazon and could not find your deal.

OP, may I request the amazon link?

Edit: will these do the trick?

100 x Magic Sponge Eraser Cleaning Melamine Multi-Functional Foam Cleaner https://www.amazon.com/dp/B01LZB2HOQ/ref=cm_sw_r_cp_api_i_UbJHDbK17KNA9