Hello Tony,
Without the exact recipe it is a bit difficult to help you with this problem, but I took the liberty of trying a recipe with the following ratio:
- Castor Oil - 4%
- Mango Butter - 32%
- Shea Butter - 32%
- Kokum Butter - 32%
I noticed that those butters are rich in stearic acid and in oleic acid. Stearic acid is good for a shaving soap, since it gives it a very long usability rate and it stabilizes the foam. what is lacking is a foaming fatty acid (the best one is lauric acid). So you need to introduce an oil to generate the foam and thus the glide. I suggest you add coconut oil (or lard, tallow, palm kernel oil, laurel berry oil, ...).
I would suggest this recipe as a starting point:
- Castor Oil - 4%
- Mango Butter - 18%
- Shea Butter - 18%
- Kokum Butter - 18%
- Coconut Oil - 42%
Consider leaving it for at least 2 months curing and for better results at a temperature between 35 and 39 degrees celsius.
Hope this helps