The paint has cured, the fabric was soaked in hot water and then ironed to release all traces of wax. Here are the results:
Fabric #1: I used a foam stamp for the grid and a cork for the circles.
Fabric #1: Layers of wax and paint
Fabric #1: Wax removed
Fabric #2: I used a foam stamp for the flowers
Fabric #2: Layers of wax and paint
Fabric #2: Wax removed
Fabric #3: I used a metal whisk to stamp the swirls.
The fabric looked identical with and without the wax layer. I suspect that because metal is a better conductor of heat, it made a clearer impression on the fabric. This was the final piece, so it's also possible that the wax was warmer.
If you are patient, and let the paint cure for 2 weeks before you remove the wax, very little paint will wash out. Next time, I'll use Dye-na-flow paint instead of Setacolor.
Lots of fun! If you decide to try this, I would love to see the results.