If the sealant has not yet cured and has been spilled on a non-porous or smooth substrate, it can be removed using Swipex, or a dry cloth and white spirit. Porous surfaces are either difficult or impossible to clean. Even non-cured silicone will likely leave a stain behind. We therefore recommend that the upmost care is taken when working on porous surfaces and to always use masking tape for protection. Immediately remove the tape after using the finishing solution to prevent skin formation over the masking tape.