Simple to apply, wait 6-8 hours on area and no scrubbing required Its fast acting, good to apply on tiles, silicone sealant (around windows, sinks and baths), shower-heads, Pool and more it is gel type, easy to use and effectively acting for a longer time Perfect for tiles ,Silicone Caulk, Sink, Kitchen, Showers, Bathroom Give it a try before striping the caulk off and redo it. This product is NOT suitable for using on the surface which is not white color. Skylarlife Grout Silicone Caulk Whitener Best for Home Sink, Kitchen, Showers, Bathroom and Floor Tile (1-Pack)