32 fl OZ/.95L - STAIN-PROOF® Waterbased Penetrating Sealer, formerly known as Stain-Repella™, is a penetrating, invisible and breathable water-based sealer which protects porous surfaces against stains to keep surfaces looking great. STAIN-PROOF® Waterbased Penetrating Sealer, formerly known as Stain-Repella™, is a penetrating, invisible and breathable water-based sealer which protects porous surfaces against stains to keep surfaces looking great.