Mark, you heard right. In the lacquer days, before modern flatting compounds, we used talcum powder to flatten lacquer and enamel paints.Don't know how durability in modern paints would be affected, but i might just try and find out.By the way, early plastic filler(bondo) was simply talcum powder and fiberglass resin.Thank God for modern technology, as modern fillers are very, very good in comparison.