Eyebrow stencils

Has anyone used eyebrow stencils and if so do they help with the placement of the eyebrow?

Not sure I have heard of them

I’ve heard of them, seen them but never used them.
People who have used them have absolutely warned everyone else not to waste their money. They are actually shapes for adults not for babies.
It would be wonderful if somewhere along the line someone would come up with a gizmo to help with placement that is for sure!