A while back I made a batch of my Lavender Chamomile soap and it didn't come out very pretty. I was a bit short on time and I added my lye solution to my oils when it was too hot...I knew at the time that something like this might happen, but I just went ahead and poured it in and swirled. You can see in the picture below the effect this gives on the soap. The edges are a bit lighter than the main body of the bar. It is a perfectly fine soap...I used a bar and it had a nice stable lather and it smelled amazing, but it was ugly. So I decided to try and re-batch it. I got out my cheese grater and grated away all 12 bars and added the shavings to my crock-pot.
I let this cook on the lowest setting for about an hour. I added 1/4 cup water to help soften it a bit and mixed. This continued to cook while I added a bit of water every 30 minutes of so. I had to resort to using my potato masher to really mix the soap. In the end it cooked for a few hours and I added about 1 cup of water. I did add a bit more Lavender Essential Oil too. It looked like really lumpy mashed potatoes. You might want to add less water, but I wanted to make sure it didn't stick and burn to the bottom of my crock-pot. (I re-batched a different batch of soap and hardly added any water...I really didn't see any difference in cooking, etc - maybe this is personal preference and trial and error depending on your initial batch). Once you are done cooking, you have to act quickly to get it in your mold.
Here is the before and after soap - both excellent qualities, but a bit of an enhancement in look.
And here is the other batch of soap. It is all the shavings I've been saving when I trim the edges on my bars with a veggie peeler. In the crock-pot they went...cooked and mixed with a potato masher for a few hours. I added hardly any water and scraped into my mold.