I'm having the same issue tjc1. I have some partially built combs with some uncapped honey which I exchanged for full frames and have been trying to get them to clean them out. No luck at all so far. I tried putting it out about 100' in front of their hive, no one touched it all day. Not even ants or wasps or anything, but I did have them in an open plastic tub. I tried putting the frames up-side-down in a super above the hole of the inner cover. Left that on for a couple of days, nothing. Turned them around to hang instead, maybe 50 bees on them, 3 days later, feeding. lol They still all seemed like they have the same amount of uncapped honey. lol Recently I've read that if you give them another empty super underneath the comb you want robbed, it gives them enough space between the honey and the nest that they'll want to take it down. Idk, that's where I'm at right now. I put that on yesterday and if they don't do anything by Monday, I'll remove them, freeze them for next year, and feed them syrup again.
Supposedly, this can be done and is easily done by many from the accounts I read of people doing it. For example, in the ABC & XYZs it states, "It is also possible to dry combs immediately after extraction by stacking them on a strong colony and above an inner cover in which the hole has been left open. The bees will clean the cells carefully and will not damage the comb." Idk, as far as I can tell, my bees haven't read this darn book yet! lol
...maybe my issue at this point is that it's been at least a good week by now and it does say "immediately after extraction"...some other time I'll try deknow's idea.
So you have an extractor? Sweeet! Good luck!