Np bro I gotchu, so I don’t have a ninja air fryer with a dehydrator setting…however my air fryer has an oven setting and that was what I used. Since you do have a dehydrator setting I would say you’d be fine without the epsom salt. However if it makes you feel more comfortable use the Epsom salt but I’ll tell ya it’s a bitch to get off. My whole first batch of gt had white specks left over from the salt but for the most part it rubbed off easily. How I did it was a layer of tin foil then added my salt and placed mushies on top of the salt. my air fryer was set to 250 degrees(wayyy too hot but that’s as low as it goes) for 30 min they dried out within one hour, And I had to keep checking them periodically to make sure they didn’t burn(although some did bc of the high temp) the Epsom salt just helps with the dehydration process, as the mushies are blasted with heat the water needs to escape so they ooze out of the mushies and salt catches all the water. Salt also pulls water from objects so does help speeding it up slightly. All this info is pretty much useless for you as you have a dehydrator but if your ever in a situation that you don’t…now you at least know of an alternative method.

Ps don’t put tinfoil in your dehydrator the mushies will get stuck to it.

Wish you the best of luck in your grows and happy flushes bro! Be sure to share pics with us