It's actually quite easy to detect. You'll need a fluorescent lamp, a variac and a pair of wrap around 3-D glasses. Let your amp warm up for 1 hour while driven to output 1/3 its rated power. Place the lamp approximately 1 meter above and pointed at either the amp's or the speaker's binding posts. Turn off all other light sources in the room. Set the variac to the standard voltage in your area and turn on the lamp. Raise the variac's output voltage exactly one half semi-tone above your area's normal voltage. Now the hard part -- rapidly fluctuate the variac's output voltage over a quarter semi-tone range, this is known as "voltage fluttering". With your 3-D glasses you should now be able to see a slightly purplelish mist being emitted from the binding posts. DO NOT BREATHE THIS MIST FOR EXTENDED PERIODS OF TIME! Stop fluttering, turn the variac back to your standard voltage, turn off the lamp, but keep on the 3-D glasses. Remain in the darkened room for 10 minutes.
Seriously, notice the alliteration - Moseft mist. It's a nonsense phrase invented during the cocaine crazed 70s by a writer trying to be clever. It's supposedly a kind of softening and homogenization of the sound. If you think you understand what the last sentence means, then maybe you'll hear it too. Otherwise, it's not something to be taken seriously.
