How do dark wizards control Dementors?

The Ministry of Magic appears to use the Patronus Charm to control Dementors. This evident by Dolores Umbridge in the following scene:

At the foot of the platform, a bright-silver, long-haired cat prowled up
and down, up and down, up and down, and Harry realized that it was there to
protect the prosecutors from the despair that emanated from the Dementors:
That was for the accused to feel, not the accusers.

_{Harry Potter and the Deathly Hallows: Chapter 13 – The Muggle-Born Registration Commission}

In general, I think there is no other reason for the Dementors to abide by the ministry other than the threat of the Patronus Charm. Though it can be argued that this threat is not nearly enough, and eventually the Dementors do leave their positions in Azkaban to join Voldemort, the ministry appears to think they enforce their control over the Dementors somehow.

"Yes, you have," said Fudge forcefully, "and I have no reason to believe that your views are anything other than bilge, Dumbledore. The
Dementors remain in place in Azkaban and are doing everything we
ask them to."

_{Harry Potter and the Order of the Phoenix: Chapter 8 – The Hearing}

It appears that Dementors, as a group, have a will and can be communicated with and follow orders. It also appears as if they can disobey if you have no leverage over them.

Dark wizards generally do not produce a Patronus. Some can but most of them do not bother as stated by Rowling.

From a Leaky Cauldron chat:

Samantha: Was snape the only death eater who could produce a full patronus

J.K. Rowling: Yes, because a Patronus is used against things that the Death Eaters generally generate, or fight alongside. They would not need Patronuses.

Does that mean that they have some other method of controlling the Dementors? It is true that they "generate" the same things that Patronus is used against, though generating these things would not protect them from the Dementors. They can still suffer from the Dementors’ powers and without a Patronus most of the dark wizards have no protection.

If we consider the "Wonderbook : Book of Spells" as canon, it could be dangerous for a dark wizard to even attempt at casting the Patronus Charm. Such trial by a competent but unworthy wizard or witch attempt the spell could end horribly wrong. In Raczidian’s case, he was covered by maggots that engulf his flesh.

How do dark wizards control the Dementors? Why do they ally themselves with a creature that could be dangerous to them?