just to run by experienced people,
I have a porcelain tile floor, OFF enough to create rock in new toilet. I will be using plaster method to create base. I thought i might use clear contact paper cut to base shape and stuck down to tiles so as to ease release of plaster in future if a new toilet shape is ever installed.

Then under toilet I thought i can coat with moisturizer to act as a mold release so to speak to aid in the same issue ( release plaster). better than greese or WD 40 on raw un-glazed porcelain. Any thought's on this approach?
It is just an idea and came from many posts of issues with hardened plaster after time.
Thanks all....