Thank you everyone for the input. I am going to try it if my Super ok's it, and your right it is expensive! I ordered the slow drying clay as I figured it did dry quickly.
My class size is total 45 but will be no more then 15 at a time. I will work with two to four students at a time on the clay while the rest of the class is working on something else. I am planning on doing a charm nothing more difficult at least this first year. I ordered some interesting beads to add and have some glass India beads as well the students should be able to make a nice charm bracelet or necklace with a unique silver charm.
Those of you that have worked with it do you think 70 grams is enough for 45 smallish charms?