Maybe a CO2 fire extinguisher at close range after dark using only moonlight. You should catch all of them. Follow up with Sevin dust in the hole, again at night if there is still any sign of life. Or you might try just the Sevin dust but it may take a while longer. Periodic applications should prevent any new bees from re-establishing a hive. Let us know how well it works out.

How would CO2 work when bees are inside? Treating bees with poison might kill them eventually maybe, ..not something that should be done, but doesn't stop bees from entering again down the road because the scent will be around as long as comb are inside. All needs to be removed, descented /washed.

No, a hive nearby will not make them move out,...you'll end up heaving two hives.

Since this posting my husband contacted a pest control shop to see what we could use to get rid of them. They put him in contact with a guy who removes bees. (We have been down this path before) This guy stated that he will bring out a hive, and use some type of lure to get the bees to move the comb and their hive to his hive. He said something about his hive having only "drones" in it and them making a queen? He said he would then show us how to clean up so that new bees don't come back. He's not going to charge us because he is taking the bees so I guess we are not out anything except hopefully the bees. Which he is welcome to keep. I have my doubts but I am willing to let him have a go of it. Especially since it's free. He is coming in late April or early May, when they become active. I will let you know how it goes. Cross your fingers

I think you must have misunderstood him. Bees never move comb. Assuming his attractant is another queen, the worker bees will not swarm to her because she won't smell right to them. Also, drones cannot make a queen because drones are the male bees and do not lay eggs, gather nectar or pollen.

I used to go out and get bees from local homes, sheds and barns. About 1/2 the time, the insects in question were wasps. I have dipped bees out of chimneys, removed them from walls and ceilings, taken them out of hollow trees. Unless the queen is removed, the colony has no incentive to move.

In some situations, killing the hive is the only remedy. I never killed a hive, but I was usually able to convince the homeowner to allow me to take a piece of the ceiling down, cut the wall open or whatever it took. If you cannot open the column that is their home, poison is the only alternative unless they have something new that attracts the queen out.

Do you have a pic of the place they go in? There is a device called a bee escape that allows the bees to leave but won't allow them back in. I did use this device once when I had a weak colony and somebody who wanted a hive removed. Placing a bee escape at the offending hive, I put the weak hive with a 2nd top entrance with drawn comb and a queen excluder near. The majority of the bees did go into the new hive after a few days, then I smoked the offending hole. This drove out the rest (most) of the workers, but even then the queen did not appear. We killed the queen, plugged the whole and I left.
The homeowners told me that when insects got in and destroyed the comb (as they inevitably do), they wished they had just let me take a piece of the wall out because the honey oozed into the house for weeks and the drywall was pretty much stained for all time. (Paint doesn't stick long to honey infused drywall.)

Good luck, let us know how it turns out. Something tells me either you have a large column (8 inches or more in diameter) or a very crowded hive.