Nikwax TX. Direct Wash-In. Nikwax TX. Direct Wash-In is an easy to use waterproofing product specifically developed for wet weather clothing. Nikwax TX. Direct Wash-Inâ ¢ provides highly Durable Water Repellency (DWR) which develops on air drying. Nikwax TX. Direct Wash-In maintains the breathability by allowing moisture vapour to pass through the fibres and is recommended for Gore-Tex items. Nikwax TX. Direct Wash-In is applied in the washing machine which ensures the DWR (Durable Water Repellency) treatment penetrates throughout the entire fabric of the garment including seams, tapes and cords. Nikwax TX. Direct Wash-In is non-flammable, contains no harmful solvents and is free of harmful volatile organic compounds (VOCs) and fluorocarbons.