Yeah, the UO Assist organize agent can put all items of a specific type from the top level of a pack into a specific container. Just remember that you need to count resources for that bag (or at least open it with auto-counting active) for the organize agent to recognize the bag, and don't accidentally have something of that type you want to keep in your backpack (like your spellbooks, if that's the item you're donating at the time). Not played around enough to know if something similar exists for the EC.
I use it for cleaning up my pack after trading in 30 Tailor BODs for new ones (then having 2-3 BOD books in the bag where I can manually sort them between cloth, leather, and sometimes BODs that I know I won't be putting toward LBODs). It's also good (using two different bags, since there are 3 possible organize containers) for sorting out BODs and smith hammers into one bag, prospector tools and mining tools into the other, when doing Smith BODs.