Yup I hear ya. We’re right in the middle of fruit fly season and it really doesn’t matter how spotless we keep the place, there will always be garbage and smells down the drain. I use the apple cider vinegar / Dawn dishwashing soap method as well (in mason jars with tiny holes in the lids). I found the trick is to have at least 2 in the kitchen and 2 in each bathroom. If you leave a particular window open all the time, but one beside it. I don’t think you’ll need to change them out before your guests leave, if you have enough vinegar in them.
Good luck!