When I have used calendula, I infused it in my oils. When I was ready to soap it, I strained it out. Once my soap was to light trace, I added about 1T ppo (of the oil infused calendula) back into the batch. I tried to take out as much as possible because the stick blender chops it up pretty good. I sprinkled a few petals (dry) on top the soap once I was done making it. It turned out nice IMHO. HTH