Removing Mold Stains from Siding is Simple with MiracleMist! This is what happened when we were asked to compare. A large customer asked us to compare MiracleMist to products sold by Walmart.We did. Here are the results! MiracleMist Instant Mold & Mildew Stain RemoverRated 0 out of 5 $17.99 – $45.00 Select options Watch these videos to see what customers are saying about the MiracleMist System.