@Inna22
Spiders eat insects and they keep the numbers of bloodsucking, disease spreading, crop destroying pests under control. Get rid of spiders and we will have an even bigger problem...but hey... humanity knows best ....and certainly an Airbnb guest experience is far more vital 🙂
"what is a reasonable amount of effort I should put into this?"
well, if you have a guest with arachnophobia then the effort has to be to ensure there are no spiders...period.
Failing that I would warn arachnophobia sufferers before booking that you cannot guarantee there will be no spiders and that you do not offer refunds purely on the existence of a spider
I did see some guy put duct tape along the windows to trap spiders coming in through those ....but every time you open the front door ..well...and every little hole in the brickwork...well ....roof eaves...well ...good luck with eliminating them completeley !!
I do keep the plug hole covered in the bath and shower and advise guests to do the same, when not in use
For Airbnb Plus the requirements merely states "There are no signs of pests " ... spiders are not classed as pests.