Explosions don't work that way in space. Very little energy goes into
moving the object. Almost all of it either dissipates into space or is spent breaking a large rock into many small rocks that still hit your planet.
You need to impart kinetic energy and quite literally push the rock away. The only reasonable way to do that is throwing inert kinetic projectiles.
Think about starting a Newton's Cradle by lighting a firecracker under it instead of dropping one of the balls. Technically the firecracker has an order of magnitude more energy, but basically none of it is translated into 'useful' kinetic motion.
