Most biological and geological porous media are typically characterized by dead-end regions with stagnant flow that are inaccessible. Understanding how micron-sized colloidal particles including contaminants, fine powders or biological entities are transported along with nutrients or dissolved salts through complex porous media is not only of fundamental importance but also crucial to a plethora of technological applications. The precise control of such processes is restricted by the inaccessibility to regions in the intricate porous matrix. On the other hand, diffusiophoresis, referring to the motion of microscopic colloidal particles driven by local gradients of salt concentration, has been demonstrated both theoretically and experimentally to be a powerful particle manipulation tool in relatively simple microfluidic setups. However, hardly anything is known about the effects of diffusiophoresis in complex porous media. To this end, first, I consider a hyper-uniform dead-end pore structure and perform pore-scale simulations to demonstrate how diffusiophoresis induced by local salt gradients at pore-scale impacts macroscopic dispersion of particles. Using an analytical model, I derive a link between the diffusiophoretic mobilities and the fraction of particles trapped within the dead-end pores to illustrate that diffusiophoresis effectively alters the initial fraction of particles within the dead-end pores. Second, I numerically demonstrate how spatial heterogeneity of the host media can be exploited to enhance diffusiophoretic transport by considering a medium with varying degrees of water-saturation. My results suggest that diffusiophoresis can provide a means for controlled particle transport and manipulation in porous media.