“If someone is an open homosexual in the military, that causes all kinds of problems which we’ve only just begun to see.”
You cannot kick them out because people now know their preferences. Attrition is the best and most legal hope.
Yes, you can. And you have to.
How could you get rid of them with Attrition? First, you would be accepting the premise that they should be tolerated. Then, all you could do is try to make them uncomfortable. The debate would become, "How do we best accommodate homosexuals (mischief makers) in the military?"