Let’s say that you are up against a demon, but you have no clue what it’s name is. Let’s say the spirit is causing the person to experience deep feelings of irrational grief or sadness. One tactic that I have found helpful is to describe the demon if I don’t have it’s name. I might confront the demon(s) by saying something like, “I command the spirit or spirits that are responsible for this grief, sadness and torment to come to attention in the name of Jesus!” From my experience at least, this seems to get results quicker than simply referring to the spirit as “unclean spirit”. Once I describe the demon’s function or activity, then I will often refer to it as unclean spirit or devil as I continue to be persistent in driving it out.
Of course, if you have the actual name of the spirit, that is the best way to get it’s attention and force it up to the surface where it can be easily dealt with.