Camping & Hiking Equipment
Nikwax Tech Wash/Tx Direct Clean & Proof Twin Pack (1Litre)
All waterproof clothing (Gore-Tex, eVent, etc) requires water to bead on the outside of the garment for it to be breathable. A Waterproof textile can lose 75% of its breathabilty if it no longer beads water and it 'wets out'. Clean with Tech Wash...
https://www.bizrate.co.uk/camping_hikingequipment/nikwax-tech-wash-tx-direct-clean-oid34475338974.html