As I said, yes, I have used foam and silicone in the past. But I am learning. And there are different ways in building vivs. Clay is not that bad, I read lots of great clay viv builds on different boards. I haven't mastered the art. Now it's not because I have used these materials that I need to use them again. I am trying to reduce my footprint. Now I have a few cans of foam and tubes of silicone that are lying around. I will used them. But for me, that's it. I have talked about using cork boards naturally pressed and that will be my next move. Now my philosophy is to each is own. Personally, I'd like to try a greener approach.