I think most of us have had bad house guests like that and feel your pain. In fact, it was experiences like the one you described that prompted me to write the article. When my husband's friends (who I had never met) left their daughter with me all day to go wine-tasting, I knew I had to grew a spine and speak up. They were totally using me and didn't give one whit about my welfare (I was 8 months pregnant and had a 2-year-old at the time)! With that experience, I declared: “Never again!” You may be at that point as well.
While I'm unwilling to label your teenage niece and nephew as rude and lazy, I will say they were totally clueless. With their limited life experiences, they have no idea all the effort it takes to prepare a home for guests (and the expense to boot). They have no notion how stressful it can be when people are messy, inconsiderate, unhelpful, and take everything for granted.
If their parents were also staying at your home, they should have instructed their kids to pick up after themselves. If they didn't, they were being negligent and the blame should be placed on them, not the teens. If the parents weren't willing to act as parents, there's not a lot you could do without causing a huge family rift. Scolding, instructing, or criticizing other people's kids never goes over well-- no matter how well-deserved it is!
If they come again, I'd give them the names of a few good motels in the area, explaining quarters were just too tight during their last visit. After much trepidation, I did this with my sister and her kids when they were growing up. It turned out to be the best thing I ever did. We all enjoyed the visit so much more, focused on doing fun activities together, and all my resentment faded away. We all felt a lot less stress.
If their parents weren't there, you should have spoken up and set down some basic housekeeping rules: put your dishes in the dishwasher, make your beds, set the table for meals, or whatever else you thought was reasonable. You would have been doing the teens a favor to teach them proper etiquette when staying at someone's home. From your frustration with them, I imagine they also neglected to take you out for a meal, bring you a gift, or express their gratitude. A lack of awareness and appreciation really takes a toll on a host.
I'm sorry you had such a stressful experience with your bad house guests. But please use this it as the impetus to establish ground rules for the next set of visitors. If you don't speak up about your expectations, you might have another frustrating time. Good luck!