I've never tried it, but if I were to, I'd use a tall container to simulate the blender shape.
I have no idea what makes the frosting gel, but it must be the agitation in the small container.
I've refrigerated the frosting after I frosted the cakes, and it turns firm and fudgy. The firm texture would make it hard to spread, but it's really not such a bad thing smileys/smile.gif