how do i clean satin shoes?

You are dealing with some very delicate fabric and if previously dyed to the ivory color, cleaning might affect the color causing spots, crazing or crawling of the fabric, etc. I would take the shoes to a dry cleaner that specializes in wedding attire and get their opinion. You might find it cheaper to replace the shoes, through a wedding shop.

If you wanted to try to clean them yourself, I would first try vacuuming as much dirt, dust as you can, then I would try seltzer water, this could water spot your item, but it might also save the item. Be sure to blot and redab on the seltzer water with each cleaning attempt. you might need to try this a couple of dozen times.