Judy,
I wouldn't even try..it's not worth the soap unless you do a one bar batch or something small. I do a small batch and seperate it into plastic cups and then drop the fragrance in using a straw and then stir to mix. I make about 12 1 oz soaps to sample the fragrances. It has helped me alot not to waste the time and money on something I don't like. I now have about 60 little 1 oz soaps in little half plastic cups in all phases of curing. It allows me to see acceleration and discoloration and how the soap fragrance matures from days to weeks to months. I highly recommend it to everyone.
Here is one of my first sample batches...actually I think there are 2...I mark the cup with the name and maker, make a batch to light trace and have all my bottles already in order of the cups, with lids off and straws cut and I put 28 drops per 1 oz I think then mix well and note. Then I go onto the next...by the end of the batch it gets a little thicker but I can do 12 in about 5 minutes now. I used styrofoam but now use plastic cups. Actually, next time I'm looking for the little cups Agriffin used for her latte soaps.