Demons can smell like sulfur, roses, cologne...anything! They can also appear as: an angel of light, a dead person or child, a spirit guide, a healing spirit (reiki), an alien, a fairy, a dwarf, a spirit animal etc! We can't safely discern them! The safest thing to do, is let Jesus and his angels protect us.
The recommendation is therefore that the stimulation should be applied with a 2500Hz carrier medium frequency sinusoidal alternating current, burst at 50 Hz (10ms ON: 10ms OFF) at a maximum tolerable level.
Hmm, what? Yes, humans, under special circumstances, can hear radio-frequency pulses in the range of 2.4MHz to 10GHz (corresponding to radio frequencies and microwave) as buzzes, clocks, hiss or knocking at apparent auditory frequencies of 5kHz and higher (very high-pitched).