@Dara11 I know it's tough, but you need to leave an honest review of these guests- try not to think of reviews as negative or positive, but honest. Keep in mind that you aren't reviewing them as people, but as to their suitablity as guests. That's the whole purpose of reviews- so hosts can make informed decisions as to whether to accept a guest and guests can make informed decisions as to what places to book. Yes, they will read it, as they should- they need to know that the state in which they left the place is unacceptable. And other hosts need to be warned, as I'm sure you would have wanted to be warned, or you wouldn't have accepted their booking. We do no one any favors by shying away from speaking the truth.
IMO "nice" is a highly overrated virtue. You say they were respectful, but leaving such a pigsty, ignoring your no-smoking rule and making off with all the extra toothbrushes and such is totally disrespectful behavior. Being nice and friendly in conversation is easy, but isn't at all valuable to you if you have to spend 7 man-hours cleaning up after them.
As a fellow host, I don't need to know all the gritty details, but in general terms, I want to know if the guest left a disaster area behind them, ignored house rules, etc.
Most guests have some redeeming features, and you can use these to create what some refer to as a review "sandwich". Mention something positive to start, move on to the negative stuff, end on a decent note. For these guests, something like "XX and her husband were very nice and friendly on a personal level, and their baby was adorable. We had several lovely chats over the 2 weeks they stayed, which we enjoyed. Therefore we were shocked to discover the state of the place when they checked out. Every nook and cranny was unbelievably filthy, with several items damaged beyond salvaging. Our no-smoking rule was ignored, entailing picking up dozens of cigarette butts strewn around in the grass and found evidence of smoking inside, as well. Cleaning time required was 3 times what is normal after our other guests have checked out. Although we were extremely disappointed to find our place so disrespected, I feel that XX and her family could be good guests in the future if they attended to cleaning up after themselves, taking good care of the host's linens and other amenities, and followed the house rules, as they seemed to be nice people."
Of course, you will write the review in your own words, but that gives you an idea. You can post a draft review here on the forum if you want feedback from other hosts before you submit it. If you post a draft review, or anything else on the "Host Circle" section of this forum, only hosts can access that section, so there's no chance that your guests can see it there. The "Hosting" and "Help" sections here are open to anyone.
I wouldn't mention making off with the toothbrushes and such- it's not uncommon for guests to assume that whatever they find in terms of amenities are theirs to take. It's a learning experience for you- only leave enough in the unit for what you think is necessary for the number of guests and length of stay. Let guests know to ask if they run out of anything. Some hosts have had guests make off with entire boxes of snack bars, entire flats of drinking water, etc.