Hi Mary, firstly, great job on making substitutions and experimenting with this recipe! I’ll do my best to provide you with some guidance.
Different emulsifying waxes will act differently in preparation. The watery consistency of your final product may mean that you need a bit more wax (and/or less liquid) However, it could have just been that you needed to stir and warm it on the stove for longer. It’s hard for me to say.
I’m not familiar with using soy butter. From my understanding, this product is made from hydrogenated soy oil. This means the fatty acid profile of the oil has been altered. If you have access to shea or cacao butter, which don’t undergo this process, this may both be more supportive for the skin and, solve the issue with the wateriness. If you have more information or experience to share about the benefits of using soy butter, I’d love to hear it!
Even though the consistency wasn’t what you’d hoped, I’m glad you nailed the smell and colour. If you keep experimenting, please provide an update on your findings.