Looking online, I found this. Looks really nice.
"I love, love, love this soap. I make it all the time, and it gets used up, given away, or sold within a few days of the batch coming out of the molds. It looks gorgeous and works like a charm. This is Spa Soap (well, that’s what I’ve called it anyway - you’re free to come up with a more creative name of course), and it’s one of the best-selling soaps I’ve ever made.
To make Spa Soap, you have to first whip up a batch of bath salts. Go ahead, I’ll wait. All done? Great! Let’s move on.
I don’t have exact amounts to give you for this recipe, ’cause I usually just play around with the soap base I have on hand. If you need specific amounts though, let me know and I’ll measure next time I make them. Don’t be intimidated by the extra step here - it sounds a lot more complicated than it is.
Here’s what you’ll need:
transparent melt and pour soap base
deep, individual soap molds - I use mini loaf pans, the ones that make single servings
bath salts
a shallow plastic tray that can handle the heat of melted soap
soap colourant, any colour
essential or fragrance oil, any scent (ocean scents are really nice in this one)
basic melt and pour supplies: sharp knife, double boiler, spoons, etc.
Melt a small amount of the soap base in a double boiler. You don’t need to add scent or colour at all. When the soap is melted and smooth, pour it into the plastic tray to create a thin layer of soap about 1/4 inch thick. Immediately sprinkle the bath salts over the soap, and press down gently to make sure they stick. (The soap is, of course, hot, so wear a glove or a ziploc freezer baggie over your hand to keep it protected.) Set aside to harden.
When this bit of soap is cool and solid, remove it from the tray and tear it up into pieces. The pieces don’t need to be uniform, but they shouldn’t be any larger than one inch square. Divide the salty soap bits between your molds, scattered randomly.
Melt enough soap base to fill the prepared molds. Add your colour and scent when the soap is melted, and pour it over the soap bits in the molds. Once again you’re required to have patience and wait until the bars have set - at least several hours, but it’s safest to leave them overnight.
Pop the soap out of the molds (if you use bakeware like I do, running a sharp knife around the edges of the soap usually does the trick) and smooth any ragged edges with a vegetable peeler. Ta-da! Spa Soap!
Wrap the bars in clear plastic wrap to keep them free of moisture until they’re ready to use."
Can't copy the picture of this bar, but you can see it here:
http://www.waxandbubbles.com/melt-and-p ... p/#more-70