www.randrmagonline.com/articles/86347-ask-annissa-how-long-can-you-use-a-chem-sponge-with-video

Ask Annissa: How Long Can You Use a Chem Sponge? (with Video)
January 8, 2015
A chem sponge can be used much longer than you think.
Even though the sponge looks dirty and used up doesn't mean that it’s time to toss and break out a new one. See the video below for more information.