In the old days, I heard about a process where the engine was cleaned out using a paraffin wax system that was pushed through the engine after any work was done on it that was supposed to grab anything in any little corner or crevice but I haven't found anyone who does that type of system. I still like the baking soda system as it all dissolves in water so there nothing left that can do damage. I have heard of engine blocks done with glass bead where they had problems with some residual glass beads getting into the oils system and had cylinder wall damage. I just want to offer an alternative system that is absolutely safe. You'll be super careful anyway you do it. Great project!