I've only attempted this twice, since I've only found two bats since the nails were added to the game.

However, once combining the nails with the bat, it seems that if you set the bat on the ground, it will disappear after a few seconds. Note that it doesn't warp somewhere else - it's perfectly visible on the ground for a few seconds - but it will soon vanish.

Not sure if maybe this is a glitch in the decay/cleanup system or what..