To clean white shoes strings all you will have to do is get a container, cup or glasses you can use to put warm water in. Then pour a half full cup of bleach into the cup and after either pour dish soap or pine-sol or any or any other liquid soap. Let the white strings sink under the bleach and liquid soup and shake it up a little.

Once you did that’, let it sit for a good 5:30m.  Then take it out and go run the strings in some hot water and take it out and squeeze the water out of the strings and let them sit for 2 minutes in air or wind for the strings to dry off.

Link:

Clorox® Clean-Up® Cleaner + Bleach