This stuff is great for giving your wettie, rashie etc an occasional wash in. A bottle lasts ages.
As for your kites, if you really feel the need to wash/clean them can I suggest pumping them up and securing them in the back yard etc, hosing off then cleaning with a sponge and a neutral detergent. Then wash off again and be sure kite is dry before packing up again. Just my 2cents worth.