We have these and we do not use them, instead we bought a sponge shelf that sits in the sink and allows the sponge to dry out properly.

Umbra Sling Kitchen Sink Accessory, Single-Sided Sponge Holder, Black https://www.amazon.com/dp/B01I58U0W6/ref=cm_sw_r_cp_api_glt_fabc_X9MKED3K2ZPCZY9KBG9A