912/913 Gill Style Breathable boot after care is as follows:

Clean. Remove salt and grit by washing under a tap or hose with fresh water. The outside of the boots can be cleaned with a warm non-detergent soap solution and rinsed thoroughly. Use a stiff brush to remove stubborn residue. You can also clean the inside of the boot with fresh water and a non-detergent soap. Wipe well to remove excess water inside and out.

Dry. Gill Breathable Boots should be allowed to dry naturally away from a direct heat source. You can improve the drying time by placing screwed up newspaper inside the boots. For best results dry for at least 48 hours.

Protect. Once fully dried, your boots can be treated with a Shoe Care Care Product such as Nikwax Conditioner For Leather. This will soften the leather and add a degree of water-repellency to the outside of the boot.