The alternative is to treat people as human beings, with kindness and dignity.
In reading the scriptures that the Watchtower uses to justify shunning, you might think about the fact that there is no mention of a secret committee of three elders, an official announcement or use of the word disfellowship. Those are things that they made up and I think they have gone far beyond what the scriptures intended. The rules are set up in a way that often leaves elders with little recourse but to disfellowshipped, the process is very much stacked against the person who has been accused.
My opinion is that if you have a member of your congregation who claims to be Christian but who you know is openly acts in a way that is contrary to Christian values, then you should then stop associating with them. It's something that an individual would decide based on their knowledge of that person and their conduct. It's not based on a one time mistake and it doesn't apply to people who aren't associating with the congregation.
For example, a man leaves his wife and lives with another woman without getting divorced but still attend the meetings, then you would stop talking to him. But if a man cheated on his wife once and you happened to hear about it, you would not stop talking to him because everyone makes mistakes. Or if someone leaves the religion and then did things contrary to Christian values you would not need to stop talking to him because he is not claiming to be Christian so there is no need to do anything.
I believe the Watchtower uses shunning to keep and maintain control, not primarily to keep the congregation clean. There is a lot of evidence that the process is unfair, in that elders and their families are treated more leniently, that women are penalised more than men, and that it is often used even when the person has done nothing wrong, or has has expressed sincere repentance. It places a burden on family members who feel they must shun, even when they know the person has done nothing wrong or is repentant. It's a cruel system that has resulted in many broken families and suicides, there is nothing remotely Christian about it.