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.
1 Vaguely speaking, the center frequency or the frequency of a carrier wave (radio wave). 2  The nominal frequency or the center frequency of an analog frequency modulation, phase modulation, or double-sideband suppressed-carrier transmission (DSB-SC) (AM-suppressed carrier), radio wave. In very technical language: The nominal frequency or center frequency of various kinds of radio signals with digital modulation -- provided that the message bit stream is a random uncorrelated sequence of equally probable ones and zeroes (marks and spaces).