I think your guests were really dirty and probably bought the roach with them but hey maybe my bins are full of them at night and I just don’t know. Plus the floods would have bought them out of the woodwork. My ‘restorer’ cancelled today as he is still flat chat assessing the damages around town. He was even expecting me to be home NYE when he ‘popped by’ unannounced. Delusional! I think spray next time you clean and leave some of those traps hidden under dark warm places they hide. Plus give your street bins a good disinfect and power hose out. I have traps for ants hidden everywhere, including on both my bins.
And yes the rubbish is a constant battle with some guests, specially those who eat take away that have a lot of packaging like pizza boxes. They never ever recycle either or crush things like milk bottles, shoe boxes etc like I do so the regular trash which should be minimal is max.
Maybe with any large groups specifically mention how important recycling is in your area and make sure you have a separate recycle bin and ask them to rise stuff before putting in bin (should be common sense) cause on holidays some people become super lazy and unconcerned about our beautiful bayside environment.
Get yoursel a journal too so you can write down the positives and negatives of each guest and what you have learned and you can write a book in a year!