I can’t say for sure this is the case with the Erie synthetic brushes, but there are synthetic brushes in the detail world and it says that they have to be soaked in water for several minutes before using. If that is the case, that probably won’t work on a ss where they can dry out and then have to be ready for use at any given time. I’d imagine they could be dry if not soaked properly and probably not great for cleaning or rough on the surface. Again, that might not be the case with theses foam masters though.