A friend of mine tried the vinegar method, 20mg in 15% vinegar held at 60-70C for 2.5 hours with a small candle until the vinegar was almost entirely evaporated. He took half of it rectally and the effects were entirely unchanged. He is convinced that the substance was not actually converted, since it remained exactly as potent as 10mg, it still took 15-30 minutes to come on (though it should have been faster if boofed and no longer a prodrug), and it also had the same tiring effect that people sometimes complain about. Though having never actually taken pure psilocin, it could actually just be identical in effect. Magic mushrooms seem to be very very similar to him.
Maybe vinegar just does not work?
I wonder why though, since the pH would be around 2.2 or so and 2.5 hours is plenty of time as well. Plus it seems odd that there were no losses from evaporation.