I made this to hold the brass wire sponge used to clean my soldering tip. It is designed to hold one of the 12g sponges that I bought here: https://smile.amazon.com/gp/product/B00NS49LPU/ref=oh_aui_detailpage_o04_s01?ie=UTF8&psc=1 , but I assume that others should fit as well.

Designed using Fusion 360.