I don't think I like the idea of running a engine with no
oil as sometimes a worn
oil pump that's empty might not pick up the new
oil. One interesting fact is, if you drain a Nissan Nevara and go to lunch, If you come back from lunch and top it up. It will not pick up the oil. Modern stuff is wonderful.
For a good flush, we used to drain the oil, then half fill with oil and kerosene. Idle the engine for 15 minutes. Then drain. It would really clean out the insides. Then when you refill it, the oil would look clean after a week. It doesn't mix with dirty oil that was left in the engine.
JD