Though the labels will detract a bit from the clean lines, sales are all about good packaging and the smell. A catchy name, some sort of funky wrapper, heck sign them all by hand like a work of art. Advertise they are signed!
Since I am assuming you will be packaging them all the same, the over all effect should be the same. Yes of course leave some unwrapped. Maybe cut some bars up into tiny rectangles as free samples. Maybe set some bowls of the ingredients you used on the table, ground coffee, calendula flowers, peppermint.. green clay... whatever... just for effect. I am much more apt to buy handmade soaps when the booth is more tactile. Soap is so tactile, I like to touch them, smell them, take a sample with my purchase...
I agree with the multilevel idea too.