My prefered method is using the PS nut. Have done it this way many times. Have done it without removing the glow plugs although I remove them once/year to inspect or replace anyway and try to co-incide the jobs. Using a remote switch works o.k. but I have a vision of how difficult it is to change the starter on these cars.

I have never done it using the crank nut since I work alone. I may look into gwizzer's method next time.

IRT accidental engine starting, I don't think it can happen without the key turned since the fuel is cut off.