>Won't this setup have lots of debris in the syrup or am I missing something here? If so, wont it hasten the spoiling of the syrup?
It's the same method that is used on the styrofoam nucs sold by betterbee. I used it in those nucs and it worked fine. I have not tried it yet on a hive, but I will this year and will report how it works. You only have a scrap of wood invested to try it. :)
Here's what Jay Smith (who invented it) says:
"If we use a large brood-chamber, we have to do little feeding, as a rule; but there are times when the honey crop fails, or we have been a little too enthusiastic in making increase, so that we find our colonies deficient in stores, with winter not far away. All beekeepers have been caught in such a predicament at one time or another. The feeder I prefer is made by nailing a strip across the bottom-boards in the deep side about two inches back of the entrance. In fact, when order the regular bottom-board I order an extra piece like the one used for the back cleat on the deep entrance. If this is not going to be used for some time, the bees will stop up all the cracks and make it water tight. If it is to be used at once, pour melted wax or paraffin along the cracks until it is tight. This feeder costs only three or four cents and is always there and never in the way. Moreover, it does not interfere in any way with the ventilation. If a driving rain comes up, this cleat keeps the rain from beating in. If you find a colony that needs feeding, all that is necessary is to slide the hive ahead about two inches on the bottom board and pour the syrup in by allowing it to flow against the back of the hive. It will thus spread out and run down into the bottom-board feeder. A funnel can be used if preferred. This bottom-board feeder holds about ten pounds of syrup. Of course, the hive must be level to prevent the syrup from running out. If a colony needs heavy feeding, the bees may be fed three or four evenings just at dusk, and before morning they will have all of the feed cleaned up away from robbers. This is a very good feeder for stimulating during queen-rearing also. If used every day for this purpose, it is best to have a thin board about two inches wide and the length of the bottom-board across the end as a sort of lid. Then, when feeding, this cover is raised and syrup poured in." --Jay Smith, Queen Rearing Simplified
http://www.bushfarms.com/beesqueenrearingsimplified.htm