Three months for a strip is waaaaaay toooooooo long ,
Interesting comment, and parallels my own experience, the longer I left OA strips in the worse state the hives became. Could usually go a month with no obvious effects, after that the rot would begin.
However that is not everyone's experience. I met Trevor Gillbanks one time at an event, and he told me he leaves staples in his hives every day of the year. Said his hives are miteless, and do well.