I'll take you as a concerned parent who takes the time to know where her daughter is and who she is spending time with. Here's my take on your problem.
I'd let the pet rat issue go. They actually make great pets, assuming we're not talking an alley rat, but an actual PET rat and it's adequately cared for. The cleanliness of the other household is something you don't have control over and while it would make you feel better if the place was looked after better, the other parent might have a problem such as depression that keeps them from effectively keeping up a house. I was going to say that maybe that sloppy parent had some great qualities that go beyond the value of a clean house. I've known at least two women who kept houses you couldn't find a clear space to sit down in. They were both unusually fine people in other ways that served their children remarkably in the area of personal values.
Okay, but this other household does have a real problem with appropriate behavior around children. the "humping" talk has no place in front of children and if your daughter spends time at that other house, she may come home with ideas you are going to be unable to have her unthink. If she was several years older, I wouldn't be as concerned, because then her peers will be talking in more alarming ways than this mother is now, but she's only ten. While the other family could give you ample subject matter for discussion--something of value, really--it makes sense to me to have the other girl visit at your home, but to strictly limit the amount of time your daughter is at the other home. You can monitor the conversation better and as an adult, you can expect the girl to be willing and learn to expect what is allowed at your home. I'd talk with her calmly and matter of factly about things like that language. She certainly can't be talking like that at school without immediate correction, so you don't have to feel that the idea of different speech for different places is foreign to her.
I've found that forbidding children to be friends with other kids doesn't work, but talking with them does. We talk about the qualities in the other person that my child values. What makes them a good friend? What qualities do they like about that person? I have let my children be the judges of who is a worthwhile person. They haven't let me down. In one case, my older son had a friend I had reservations about. We'd discussed it, he'd been open to the conversation. The boy did one unminor, but not major gaffe at our house and was forgiven. In time, however, he began using drugs, as I feared he would. This kid had been my son's oldest friend. They had been friends for seven years or so. When the boy became a drug user, my son stopped socializing with him. Period.
Sometimes our children are very good at growing up. They need us to look out for them and to be wise about it.