131:5 If one wronged another person, who then died, he should bring a minyan of ten to the deceased’s grave and say, “I have sinned against the G-d of Israel and I sinned against this person, so-and-so.” The minyan replies, “You are forgiven, you are forgiven, you are forgiven.” The offending party should go barefoot. He should give details of the offense so long as doing so would not be a source of embarrassment to the deceased. If the grave of the deceased is more than three parsa’os (approximately nine miles) from where the offending party lives, he need not go there himself. Rather, he may send a representative, who brings with him a minyan of ten. They go to the grave and the delegate says, “I am the representative of so-and-so and I publicly announce that I have been sent by so-and-so to ask forgiveness for what he did….” If someone insulted a person after he died, he does not have to go to the grave. In such a case, he may request forgiveness in the place where he insulted him. If he slandered the deceased, the offending party must also resolve to repent for violating the ban against slandering the dead.
131:6 It is a mitzvah to go to the mikvah on the day before Yom Kippur in order to cleanse one’s self from the ritual impurity of nocturnal emissions (“keri”) and also for general repentance, just as a convert goes to the mikvah. Even unmarried men and women use the mikvah. We must be careful that there is no obstruction between one’s flesh and the water. The main time to use the mikvah is after midday. A woman who has had marital relations might expel semen for three days after, which is considered like “keri,” so the immersion is ineffective in such a case. Before going to the mikvah, she should wash well with hot water to keep further semen from being expelled. If she had relations close to using the mikvah, or close to the start of her period, she is not permitted to destroy active sperm and therefore does not wash with hot water; she should still immerse in cold water. One who is mourning, even during the week of shiva, may still wash and use the mikvah (even using hot water – Mishnah Brurah 606:24) an hour or two before nightfall, even before mincha. The rest of the laws of mourning, however, such as sitting on the floor and not wearing leather shoes, are observed until nightfall.