At the end of each season I try to target 2 or 3 of the least profitable (or biggest PITA) accounts for firing and replace them with accounts that are more to my liking. I haven't had any problem replacing them by the beginning of the next season. Have you ever tried contacting local property management companies to see if they have any work to sub out? I have a good working relationship with one and they always are able to come up with jobs when I have a vacancy in the schedule. Makes it very easy to fire customers when you know that they can be quickly replaced.