"DWR"
That's an easily searchable abbreviation for Durable Water Repellent. It is not waterproofing. It can be applied by washing or spraying. Fairly effective on jackets because it causes water to bead and then gravity causes the bead to roll off instead of seeping into the fabric and weave.
I'm skeptical about how well DWR would work on shoes. First the fabric should be clean for the application and shoes get dirtier than jackets. Second, I wonder about how well the beads of water would run off the flatter part of the shoes, the tongue and the area above the toes. Third, there will be more abrasion to the DWR applied to shoes than to jackets, think of grass and dust (you're wearing shoes on dry days too).
Oh, the good part of DWR is that it should leave your shoes breathable.
I'm giving you more information than any kind of report about how DWR has worked for me; I haven't used it on shoes. I've decided that I can handle wet feet as long as the weather is warm enough.
I ran a Google search for
how DWR works shoes
and got pretty good information.