Sometimes, when my soap is looking a little puny, and I want to change it up a bit, I remelt it using a crockpot. This has the added benefit of working lye free. There is always lye in a soap, but the measuring, diluting, breathing, and touching the lye has already been done in the soap that is used to recreate a soap. Quick, easy, and painless...
except for the grating... and your fingers.
Once it is grated, add it to a crockpot on low, add a bit of water, and wait for it to melt completely. It will need some watching and stirring - it can burn.
This is a great time to break out a fun, new mold to try.
Silicone is great with an easy release after the soap has hardened. I like finding my molds at Goodwill. Judging from how many are donated to Goodwill, it seems baking with silicone was a good idea, that has come and gone.