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.
Essentially, this type of electrical stimulation employs what is referred to as a medium frequency alternating current (in the low kHz range - thousands of cycles a second), which is delivered in a pulsed (or burst or interrupted) output. The pulsing or bursting is at a 'low' frequency, and as a result, nerves will respond.