Dr. Rachel Talks About Sponges Posted: 4:01 p.m., March 17, 2014 | Updated: 10:30 a.m., August 25, 2014FacebookTwitterRedditPinterestLinkedInEmailPrint This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. What’s the dirtiest object in your kitchen? It’s your sponge. But Dr. Rachel Lagniappe explains it doesn’t have to be.