Unlock frozen engine

I used Marvel Mystery Oil freeing up my 340, I turned the motor with the pistons facing up, and dumped a puddle on the pistons until it covered the tops of each one and let it sit, then I flipped the motor and did the other side the same way. I’ve also heard trans fluid, kerosene, diesel fuel, Seafoam, and other sauces, but I had the MMO around so I used that. After a couple weeks of doing that I tapped on the top of each piston, and the ones that were loose I either pulled if I could, or unbolted from the crank until they were all loose.