If you're looking to raise the fry, you will be better off trying to get the fish to lay on a tile (I use old ceramic floor tiles). Remove the tile the night of hatching into a dedicated fry tank. The same number of fish will hatch on the rocks and tile, but if they hatch on the rock, you will have to "fish" around the tank to get the fry, and you won't get them all.
Problems can come up because you need to keep the eggs aerated and water flowing over them. Most people use air bubbles to do this. Bubbling eggs over a tile is much easier than bubbling them over a flowerpot.
If you want to get into raising clowns, get a couple of books (Wilkerson and Wittenrich have both written good ones). You can also find one of my older posts here in the URS about raising clowns.