I also have Baltimore and Orchard Orioles nesting in my yard.  I tried the
Oriole feeder a couple of years ago and had no luck attracting any orioles.
I did attract a swarm of bees.  They emptied the feeder and moved on.  I
have also tried oranges staked to trees with no luck.  This year, the
Baltimore Oriole has enjoyed picking out the leftovers in orange rinds that
were thrown in the compost pile.  Go figure.  ;-)

Jim Wilson
Queenstown, Queen Anne's County