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.
In the classic Russian Stimulation, the 2500Hz is modulated (or burst) at 50Hz using 10ms ON and 10ms OFF periods (illustration C in the upper figure). The Ward and Shkuratova (2002) review also mentions several other reasonably early papers (i.e. before 2002) which have evaluated RStim.