Suitable for porcelain bathtubs, vinegar is a naturally acidic cleaner that will work wonders for your bathtub. Remove hard water stains and soap scum by pouring in three cups of white vinegar, while running the hot tap with the plugin. Fill the tub up so it covers the stains and allows ...
method for removing stains on finished hollow glass, fiberglass porcelain.DR. ADOLF ZOELLNER