Fresh aren't as disgusting as cactus tea, but they sure aren't easy.  They have a sour/tangy/sweet taste on top of the usual mushroom flavor.  I'm not a fan of mushrooms either.  The only time I eat them is when I'm doing this. 

I'm thinking the dehydrator and the hot water are not causing a problem.  The melting point of psilocybin is 173-176C, water boils at 100C, and I dehydrate at 35C (95F, lowest setting).  Two problems that *can* cause potency loss:

(1) Inefficiency of tea process, leaving psilocybin in the mushroom material.  Easily solvable by increasing the amount of mushroom material.

(2) Possible PH issue causing damage to psilocybin.  Apparently it breaks down when exposed to a basic environment, which is why people recommend adding lemon juice to the tea.

Hmm, dehydrator with no thermostat?  I suppose you could use a thermometer to estimate it's heat output.

Currently I have only growing and consumption experience with Mexicana A, my first try.  My second try is with Mexicana ATL7, of which I have growing experience only so far.  I tried to get Panaeolus Goliath isolated on agar, but it failed spectacularly.  (That was some crazy looking red stuff, would have been cool to see it in jars.) 

Honestly, I can't say how much real consumption experience I have with Mex A, since I can't be sure it grew right.  My second batch is growing so differently that I suspect the first batch was flawed somehow.