In the last 2 months I've flown with 2 boeing types with over 700 hours in their makeup bank. One said he flew one week a month, the other not much more. Trip dropping can be very effective if they are fat in your seat. I have never had a problem dropping a trip if open time shows you can do it. If all else fails, go to one of those message boards and offer the trip to whomever wants it. If it's a decent trip, someone will take it off your hands for you.