Many years ago I was lucky to obtain an old flat ring spanner that was a perfect fit on the ESA nut. It is 3/16" thick, the same as the head of the nut. I hold it on to the nut with the palm of my hand while applying a large hammer to the other end of the spanner. This tightens the nut such that I have never had one come undone and also means the the nut can always be undone when required using only the compression of the engine to prevent rotation. Steady application of load to the nut does not do the job.