Mix the bentonite clay with the glycerin and the essential oils in a small container to create a slurry.
Cut the melt and pour soap base into chunks and place in a microwave safe container. Heat in microwave until melted (check after 30 seconds to gauge how long it will take in your microwave). Remove as soon as melted, don't over heat.
Stir the melted soap base, allow to cool off for about a minute, then add the clay slurry. Stir in well, until evenly distrubuted.
Pour the clay soap into silicone molds. If you have a detailed mold, pour a little in and gently rap against table then fill to top (avoids air bubbles marring details). Leave to cool at room temperature.
Once cool, pop out of the soap mold. Store in an airtight container to maintain scent.