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.
Techopedia explains Burst Mode. Burst mode retrieves and transmits high-speed data via the following resources and features: Data Bus: Permits a single device to have total control over a bus until data transmission is complete.