How long do you have to use kinoki pads until they stay white?

they don't work they turn colors from sweat sp when you don't sweat..... take one and put a little water on in and it turns brown. I got them looked at the and new there was no way. cover any part of the body and it will sweat when you sleep so that's how they work. they can be used on a 1 week old and you will get the same result.