I’m afraid that dark-type service pokémon face many of the same challenges pet or battle-ready dark-types face, and there’s not much you can do about that unless you have the energy to educate (which not many people do, I know). There will always be people who are convinced that all dark-types, regardless of training, are uncontrollable beasts who will lash out at a moment’s notice. Sometimes, people can be convinced that your pokémon are harmless if you show them that they’re gentle (perhaps by having a non-dark pet or battle-ready pokémon accompany them), but this could be a distraction for your service pokémon. That and it’s not a guarantee that people will leave you alone, especially if you live in regions that are especially rich with anti-dark-type folklore.
My advice would be to ensure that your service pokémon are wearing their service vests, do your best to keep them professional at all times, and remember that you have an actual human right to bring your service pokémon with you. If a person simply gives you a dirty look, try your best to ignore it and remember that there is nothing wrong with you or your service pokémon. If possible, travel with a friend who’s comfortable with your service pokémon, as having at least one human with you who clearly doesn’t mind your absol or houndoom may be a comfort to others.
If you’re confronted by someone, however, always remain calm. I know, it may seem difficult to stay calm in those situations, especially given how vehemently some people address dark-type handlers, but it’s important to avoid escalating the situation. Therefore, if you’re in an inescapable situation wherein someone questions your service pokémon or tells you that they need to be removed from the premises, calmly tell the other person that you’re disabled, that you need your service pokémon (and, if you wish, for what reason), and that the law of your region (in most cases) allows you to enter a business establishment with pokémon of any type who are trained to assist those with disabilities.
If an employee still has an issue with your service pokémon and they are not a manager, ask to speak with the manager. If it’s a fellow patron who has approached you, find an employee and ask for assistance. And if it’s the manager themselves, remind them that barring you entry is discrimination.
Should this fail to stop the manager or owner from barring you entry or kicking you and your service pokémon out, contact your region’s Division of Human Rights (the actual name also tends to depend on the region—be sure to educate yourself on your local laws and government bodies as well) to file a complaint against the establishment. This, of course, should be your very last option, as filing a complaint means working with the legal system, which itself could be more of a mess than it’s worth, depending on your region. Nonetheless, it’s still a viable option, especially if—blazes forbid—violence was involved.
I know this might not be the answer you’re looking for, anonymous, but I’m afraid the stigma against dark-types is always going to be a problem for us humans. Even if your pokémon are nothing if not professional, there will always be one or two people who will give you strange looks for having dark-type service pokémon. Thus, it’s best to ignore those who don’t engage with you and, whenever possible, to educate those who do. Who knows? Maybe, if your town is small enough or if you frequent an establishment enough, your efforts to educate will evolve into a rapport with the owners and regulars, who can then, in turn, help others to feel comfortable with your pokémon whenever you’re in. Friendship often breeds friendship, which is why it’s very important to stay calm, know your rights, and be prepared to de-escalate and educate, if you can.
Best of luck, anonymous.