Another good maintenance product is Nikwax Aqueous Wax Leather Waterproofing. It can be applied to wet or dry leather. Apply with brush and work into seams and stitching. After two to three minutes, wipe off excess. Maximum water-repellancy is achieved with two or three applications.
Detergents leave a residue that can spoil the waterproofing.
Wash either by machine or by hand in a large container. It is important to rinse the rugs very thoroughly with plain water after washing. Treat one rug per machine. Use a commercial front load machine set on the longest wash setting and run through the whole cycle. Hang or tumble the rugs to dry thoroughly before use.