Before beginning, be sure to protect your work surface.
Use electrical tape to completely cover the soles on the sides of the shoes.
Fill the foil container with shaving cream, then level it out. Add water to the dye bottle and shake well to combine.
Drop dots of dye all over the surface of the shaving cream.
Drag a skewer through the shaving cream to marble the dye.
Place both shoes face down in the shaving cream, tipping gently if needed to make sure the shaving cream covers all the way up to the soles.
After 2-3 minutes, pull out one of the shoes and scrape the shaving cream off to reveal the design. Repeat with the other shoe. Use paper towels to wipe off any remaining shaving cream.
Allow the shoes to dry completely, at least 6 hours.
Rinse the shoes under warm running water until the water is completely clear, up to 10 minutes. Remove the tape and rinse one more time, then allow shoes to dry completely before wearing (up to 24 hours).