Have you ever tried using nail polish as marbling paint? Just regular nail polish will float on water and allow you to do a bit of manipulation to it before it dries!
You do need to work fast though, as well as using a small surface area because the polish will start to dry on the surface within a minute.
Watch the quick Nail Polish Marbling demonstration on my channel Giddy Up Workshop for how to do create these hanging Easter egg ornaments in no time. :)