I am Wiccan and have no desire to convert to Satanism. However, I have come to the Theistic Satanism DIR with a question: How does one work with one's demons? I exorised and banished most of mine, and I don't know what to do with the rest of them. Fear seems to keep them in line. How do you work with something malevolent? With creatures that have such a mischievous side? With creatures prone to lying and manipulation? With demons? Any advice on the matter would be appreciated.
Having known and worked with theistic Satanists, its mostly a non issue. Banishing takes care of anything they don't want and they don't normally make them subordinates but see all the spirits that come to them as equals. Anything that won't treat them the same back are banished.
Though I don't understand why you are going to Satanists for this, it seems to assume that Wicca and Satanism have enough similarities to make the demonology of the two compatible when it's anything but. However as I said I've worked with Satanists before and even been taught by a couple so I can try to best answer from my own experience. But as I said for most Satanists the spirits they call on are equals, anything else that won't be fair to them are banished.
So....
In my experience spirits can only hurt you if you let them. This makes possessions, hauntings ect mostly a nonissue unless someone believes it is, will become, or might be an issue. More often than not the spirit is created and fed by the person until it gets out of control and takes a life of it's own. These are easily distinguished from real spirits in that they have a theme of problems or emotions the person is having. If a demon is causing a person an emotional reaction, chances are they are it's creator and it didn’t originate outside of them.
More practically speaking, I do have a few "demons" under my control. Fear works. So does hurting them and rewarding them according to what they do (but if they try to abuse a reward I give them the punishment is usually much worse, so far it's meant that defiance is very rare). Protecting them even can let them know that while they are your property you still don't want them being mauled. So long as they know that it's in their best interests to follow you and listen to you and do everything you say. On the other end I've even killed one to make an example but I wouldn't recommend that because that kind of thing really changes you and can give you a lust you don't want to face. Hell using pain and fear as control can do that in general with the right people.
You could also try to be nice to them too or slowly work to make them better and redeem them. Whatever you want really. If they are so bad as to only kill and destroy and lie, just slaughter them for the greater good. If you can keep them under such a short leash killing them shouldn't be an issue but by god be sure it's really because they are 100% wicked and not just seemingly bad due to circumstance. I don't take lightly to killing spirits but sometimes it has to be done.
The mischievous side isn't too much an issue so long as it doesn't turn too dark. Though the fact that you can't banish them when you might want to might be something to look into with yourself. Normally belief in your ability to banish and brute force should suffice, at least in my experience. If yelling doesn't work, yell louder!
Mainstream Satanists, following the original tradition of 1966, think faith in Jujus either in the sky or earth are so much flights of fancy; bluntly nuts. And that would consitute the bulk of folks within the mature form of Satanism. But you will and are welcome to find answers from "fringe" Satanists who I think frankly are kiddos whipping their dicks around in the dark if not trying to scare mom and dad, then still dabbling in a judeo-christian framework.
This is the theistic DIR, the LaVeyan fanboy club is next door. Also your idea of fringe is unfounded, theistic Satanists are numerous easily rivalling symbolic Satanists. A lot of theistic Satanists are a bit out there, but that isn't specific to theism that's specific to Satanism in general. I've known plenty of theistic Satanists who were level people who didn't care about judeo-christian beliefs in the least. It's usually much more eclectic and open-minded than that in those circles if not just focusing on the generally positive associations of Satan.