yes a great way to do it would be to add a lattice to the cube. Then add the softbody to the lattice.
have the particles of the soft body collide with the plane underneath, and add a gravity field on the cube. Then watch it melt away
By useing a softbody, it gives your a bit more freedom to add some realism like a slight bit of turbulence as it melts, to create some ripple effect.