HDC incubation: very simple method by Don
This method is not difficult, but it is time consuming and somewhat messy. 
You need 2 rats (they need company) of the same gender. Males tend to be easier to take care of than females. There is a lot of information online about the care of pet rats, e.g., here. HDC can sometimes colonize other rodents, but not easily. 
Give each rat 10 HDC, which can be obtained from someone else who is already incubating them, or from one of the commercial Helminth providers that sell HDC.
The rats will eat the HDC if you add them to some food, such as yogurt or apple sauce. There’s no need to force the HDC down the rats’ throats, as is suggested in this paper.
After about 2 weeks, Hymenolepis eggs will show up in the rat feces, which you can look at using the normal fecal float method that is used to test feces for the presence of other organisms such as hookworms.
When you find eggs in the rat feces, it is time to feed the feces to beetles. The latter are just the adult form of mealworms (mealy worms), which are used for fishing bait and to feed pet reptiles. They are widely available from pet supply outlets such as PetSmart, but make sure you get just the regular ones rather than superworms or any other type. Some of the other ones will work but the regular ones are best.
Raise the mealworms in oatmeal. They also need a source of moisture such as a carrot.
When some of the mealworms have turned into beetles take those beetles and put them into another box of oatmeal with a carrot.
Take away the carrot for a day so that the beetles become thirsty. Then put some moist rat feces into the box and the beetles will eat these for the moisture. Putting the feces on aluminum foil prevents them from drying out too quickly. 
Continue raising the beetles on oatmeal and carrots (or other moist fruit or vegetable) for about a month so that the HDC matures. There’s no need to add any extra moisture. One grower who did this found that it caused foul smells, dead insects, and even a grain mite infestation on one occasion. Some beetles may die anyway, and this is normal. It’s a tough world for them and they have to endure the invasion of their bodies by the hymenolepis. Perhaps those that don’t make it have ingested too many eggs. While extra moisture beyond what’s in the fruit or vegetables isn’t required, the process at this stage is temperature-dependent, so, if it’s cold, it will take longer and, if really warm, perhaps 3 weeks.
Now it is time to kill some beetles and dissect out the HDC, which can be found in the abdomen of the beetles. Cut off the head to kill them. Scrape out the abdomen into some saline. Then, under a microscope, remove the HDC using a pipette (as shown in this video) and place these into some milk (or whatever you want to drink them in). This dissecting microscope, available from Amazon, works well for this purpose and is only about $150.
1. Don’s original series of posts explaining this method can be read in full here.
2. While HD eggs don’t last very long on average, it might take a long time for them all to die. Some HD eggs may still be viable at 10 days, although the viability may be reduced by as much as 90% at that point. If the half-life of the eggs were about 3 days (a very wild guess), a few eggs might still be alive after several months because there are so many to begin with. (From a university researcher working with HDC.)
3. If using a heat source to raise the temperature in the beetle enclosure, be careful not to overheat them because this could cause them to die prematurely. 
4. Most users of HDC take 30 HDC every 2 weeks, but some people take less and others more. For a detailed guide to dosing with HDC, see Self-treating with HDC.