Since swapping to soap instead of shower gel and liquid soap, I've a burgeoning collection of soap ends.
I find that soap ends stick to the same soap type easily. But what about odd bits?
I saw an article online suggesting grating odd bits of soap, mixing them with a little water, and leaving to dry out before using.
So I tried it - very successfully.
The odd bits of soap
I forgot to take a photo after grating the bits - they looked like parmesan cheese although you'll have to trust me on that.
After being mixed with a little water, it resembled scrambled eggs.
After shaping, I left it to dry for a couple of weeks.
And then used it - works fine.