We used cooking oil to help the cement from sticking onto the rock too much. Don't laugh, remember we were at the experiment stage, so anything goes that we might think it would help.
So I hoped you liked this topic. I got to experiment with ways of making artificial rock. It was a good start, unfortunately I ran out of time and had to come home back to the US. But, I am confident that we could produce premium great shaped man made rock in the future. I hope you have learned something new from this post, and if you have other ideas or suggestions, please let me know I would love to hear them. You can post a comment here or send me a message at firstname.lastname@example.org