If you do use the strips and you keep good inventory of your plants, use the no pest strips 5 days in a row.. maybe give it a 6th for good measure, then bag em up for the next crop/time should you need them.
They work.. I'd figure if I didn't break the life cycle and eliminate them after 6 days, they just didn't get used correctly or you have too big of room... 'smaller spaces' work best for obvious reasons.
That is just my thoughts.. everyone else's own mileage may vary.