Dishwasher-safe hummingbird feeder!!
http://www.firstnature.net/product_hummingbirdfeeders.phtml
Not sure that these can be put into the dishwasher - but I have to tell you these are incredibly easy to clean...ALL parts come apart...both sizes sold at Walmart - bigger is around $5 - smaller around $3
I've put the little one spouters from Walmart in the dishwasher, trying to get those bee scents off, they had no problem.
Part of the problem I've had with the ones I got at the store is that the plastic won't hold up to our summer temps/sun; they'd get all rough and the little perches would break off after a few months when I was cleaning them. These are made of a different kind of plastic that doesn't seem to get brittle or fade in color.
Dishwasher detergent residue is more of an issue with me than the hand washing. We're big enough to overcome whatever soap we ingest, I'm not so sure about hummers.
I never use soap on my hummer feeders in any form. I clean with a vinegar/water solution and once a week, I clean with a bleach/water solution. The sugar will neutralize the bleach, if there's any left on the plastic.
I'm concerned about keeping healthy birds, and they will drink from whatever feeders that are offered, whether they have any residue on them or not.
I just don't take the chance. I wash my feeders with 1 cup of white vinegar to a sink full of water every time I fill with nectar. I use 1 cup of bleach to a sink full of water once a week and let the soak.
I have several feeders and don't do all of them at once, they are rotated to where I only have to do a couple every other day or so. This way, there's always a feeder out while I'm cleaning...or I do several after dark and put them back later that night.
I've been using these Cascade packets, and they do the best job of anything I've ever used in my dishwasher. No residue.
http://www.amazon.com/gp/product/B000VKSP4C