Embodiments of a method are provided for fabricating a high temperature castable article, such as a casting mold or a core. In one embodiment, the method includes the steps of providing a suspension containing a plurality of ceramic particles and a photo-curable monomer; photo-curing selected portions of the suspension to produce a green body coated, at least partially, with uncured suspension; and removing the uncured suspension from the green body under process conditions at which the viscosity of the uncured suspension is reduced. The process conditions include exposing the green body to one of the group consisting of: (i) microwave energy sufficient to excite a dipole moment of the uncured suspension and (ii) sonic energy sufficient to induce shear-thinning of the uncured suspension. The green body is then heat treated to produce the high temperature castable article.