Oh boy! Do I understand the messy house aspect you're going through. Cleaning makes me tired just thinking about it. This past weekend I had my first visitor to the house in, literally, years, if you don't count the couple of times my mom came. She already knows how things are, so I don't even try to pick up before she gets here.
I sat here in the middle of it just wanting to cry, no idea where to start. The only help I have are two teenagers so, basically, no help at all. I finally just said "Hey, I need help" and gave them SPECIFIC tasks to do. "You, pick up everything in this room that's yours and take it to your room. You, pick up the newspapers and anything else the dog has ripped apart, then pick up the rest of the bottles and cans and empty food wrappers." Those two things right there made a huge difference. I also told my friend earlier in the week that it looked like a tornado went through the house, but I'd get as much cleaning done as possible, so he'd be prepared to walk into a hazardous waste dump if I failed to get a flash of cleaning inspiration/motivation in the next three days.
He was very understanding, but I managed to get the house picked up more than it's been in ages. My daughter walked in the bathroom and goes "Wow, this place actually sparkles!"
Anyway, moral of the story, let your guests know the state of the house and if it doesn't get picked up as much as you'd like, at least they were warned.