I just had a pumpkin carving party yesterday and we had a great time. I invited 13 kids (some were sibling groups - ages ranged from 18 mos -5yrs) and a parent over to carve their pumpkins. We had 7 kids, with 4 mothers, including DS and myself at the party. Now I did anticipate food crumbs, muddy footprints, toys being scattered, and general noisiness. What else can you expect? That's what vacuums, mops, and carpet cleaner are for.
What I did not anticipate and was VERY grateful for was the other mothers helping control the kids. When a couple of kids went up to my son's room and literally dumped out every toy he owned, 2 of the other mom's were helping them pick everything up. One mom swept the basement, which leads out to the backyard, which was covered with dirt tracked in from shoes. Another mom was helping kids with getting juice drinks and helping them get food from the table.
All thses mothers are definitely invited back to my house whenever they want to come.