A float will move it around some where a roller won't. It seems like a logical tool to me so we'll see how it works, at least somebody's trying something!
After all the poking, prodding & eyeballing I've done out there I've found the golf ball dimples are actually in the dirt & probably created by the salt water sloshing around as it dries up & then it fills the dimple with salt when it dries. There can be up to an inch of salt in the middle of them but basically nothing on the edges so you can imagine what a drag does to it.
Sid.