Interesting because the BOE I was on made these calls every year. Quite frankly, it was the most uncomfortable thing I ever did as an elder. These folks had been out for 15-20 years, I didn't know them at all and would routinely get blasted. I thought it was a strange arrangement because 1) most didn't walk away but were thrown out, 2) they knew where the KH was and if they were interested in coming back then they had the "option" and 3) shunning just makes people angry. I noticed that if someone was really going to be reinstated, they would typically come to meetings soon after being DF'ed.
And this was my attitude as a die-hard JW. Now, I really see not only the damage that shunning does but just how unChristian the whole thing is. Even as rough as Paul was, he relented in Cornith pretty quick and saw the damage.
The calling on DF'ed or long time inactive ones would probably be more effective if the shunning wasn't there. Who wants to go back to the meetings when no one will even look you in the eye? If they want to improve the numbers, they should really reconsider the shunning policy. It's just bad for business.
Edited to add: I remember one individual that I was assigned to call every year. I actually joked around with him because we talked for a while the first time I meet him. I knew he didn't want to come back and he knew (he was a former elder) that I had a box to check. So we would talk about sports for a few minutes, I would ask if he wanted to come back, he would say that hell hadn't frozen over yet, and I would laugh and say ok, if you change your mind, let me know. It was very casual. I should dig up his number and have a real conversation with him now!!!