Here's one I haven't seen on this site, and I thought the folks here were doing everything.
First you're going to need a nozzle that you can hold in your butt while you're asleep. Something with a little knob on it is best. You need just a little resistance to keep it from coming out on its own. I use the screw in adaptor fo the pipes that come with many of the drugstore bags. I don't like that type of setup, as they can leak or the pipes come unscrewed. I take the adaptor that goes on the end of the hose and then cut, file, and sand off the sharp edges. It goes in easily and generally doesn't come out unless you tug on it. I'm sure there are other ways to make a "knob nozzle".
Ok, now you get set for the enema. Take your heating pad and place it flat where you can lay your bag at a good height for an enema. I have a bookcase headboard that is 2-3 feet above the bed that is idea. But, a handy shelf, widow sill, etc., could work. Turn the pad on fairly low. For me, a 2 is about right. I may take a few tries to get the heat right. You definitely don't want it too hot in the morning. Usually I will wake up a few times at night, and I will feel the bag to see how things are going, and maybe adjust the heat.
For this you obviously need a closed top bag. One that doesn't leak, also. Fill it with whatever enema juice you like, and at a good enema temperature. Place the bag flat on the heating pad, and cover it with a towel or blanket to keep the heat in. I don't overfill the bag for this, as I certainly don't want to have a leak.
I go to bed, put in the nozzel, and then arrange the hose so it isn't kinked (he he) and I'm not laying on it. Pull on the covers and go to sleep. So far I've never had enema dreams, but I can hope...
In the morning, usually as soon as I wake up, I slowly reach out and find the clamp and open it. I don't move from the position I was sleeping in, so that I am as relaxed as possible. Thus I have gotten my morning enemas on both sides (Saturday was right side, curled), on my back, and almost on my stomach. If you aren't sure about the bag temperature, you might check that first. After just a moment when the cold water from the hose runs in, you start getting the warmth of the enema. It is usually fantastic, and always very good. Just lying there, drowsy, relaxed, and having you bottomed warmed and filled with warm water.
I usually try to take the whole bag without stopping, but don't always attain that. Sometimes, if I use my ramp nozzle, I'll set it for a nice flow so I don't have to stop.
At some point during the enema you will certainly become awake, and probably aroused. I usually roll onto my back, pull down the covers, and start to play. In the old days, when the apparatus actually worked without blue pills, I would end up with a major whack off, hopefully just when the bag emptied. Now days it is just play, but later I'll take a pill and do another bag and go all the way.
As they say, try it, you'll like it. If you do, post a reply.