Is it necessary to write down the names of those who have been slandered and to supplicate for them with specific measures, or is it sufficient to supplicate for whoever might have been slandered or wronged, to the best of one's ability?

It is sufficient for you to seek forgiveness and supplicate for those whom you have backbitten, without the need to specify their names or inform them, whether they are alive or deceased. You should frequently seek forgiveness and supplicate for them.