I was watching a DocM video the other day, and he was making a stone slab platform over a mob spawner. He said that turtles would place the slab in the top half and not the bottom, so he was placing slabs manually. I found a shortcut for that, which is to use Wand of Equal Trade on a platform of solid blocks. Then, I tried using a Filler and that works as well, it places the slabs in the bottom half of the block. Any other ideas? I wonder if a turtle would work placing them upwards.