Obivious

So I got my rx8 4 years ago but lost my license 3 years ago. Then my go burnt out the clutch 6 months later. I was doing good starting the motor every couple of week to keep it lubed. Accidently flooded and cold never get it to stay again. Had to move a couple of times and the car ended up in storage on a farm. I finally got it back and was going to start with a new fuel pump, plugs , and fresh oil. Found worse case scenario when I pulled the plugs. There is a layer of surface rust inside and sludgepiled up at the bottom of the rotors between the two spark plugs. So my question is the best way to clean this out. I'm sure I'll have to rebuild this motor soon but am curious how tough this motor can be. I was thinking of spraying oil in and cranking with plugs out and fuel fuse pulled.