I'm hosting a Mommy, Grandma & Me Easter Craft Party for the grandchildren and DILs of my friends. I have the snacks and crafts set but am stumped at one detail--

If I make a stencil of a bunny footprint, what can I use to spray the shape temporarily on the driveway and up the walkway? They do it on the roads for St. Patrick's Day.

I considered using sidewalk chalk but don't think my knees would hold out that long--it's a looooong driveway and I have oooooold knees. Ideas?