Nikwax Wax Cotton Proofâ ¢ Spray, Nikwax Wax Cotton Proofâ ¢ Spray adds water repellency to waxed cotton items. Nikwax Wax Cotton Proofâ ¢ Spray can help to prolong the life of wax cotton garments and optimises the performance. Nikwax Wax Cotton Proofâ ¢ Spray allows for direct treatment on areas that require it most like elbows and seams. Nikwax Wax Cotton Proofâ ¢ Spray is non-flammable, contains no harmful solvents and is free of harmful volatile organic compounds (VOCs) and fluorocarbons.