Typically, if you add a teaspoon of motor oil, and the readings don't go up significantly, it is a bad valve or head gasket. I am not sure what fogging oil would do to seal up bad rings in this type of test, so I would reccommend repeating the tests with a tsp of motor oil in each cylinder.
Normally your valve train wears so that the valve lash (looseness) gets bigger and so that would not hang a valve open. But, if a valve pounded badly into the valve seat, then it could close up the lash and hang the valve open a bit.
Next time see if you can determine if the 'psssss' is coming out of the intake port or out of the exhaust and that would confirm a bad valve. Putting air pressure into each cylinder from a compressor with a park plug adapter would show this right away.
And the lower than average reading in cylinder 1 could be valves or cylinder wear; front cylinders in inline sixes often show more wear.
