In my opinion, forgiveness and cleansing is given the moment a person confesses/admits that he/she has sinned. I do not believe God puts a person on a probationary period (so many minutes, hours, days, weeks, etc to make sure they don't do it again) before forgiveness is freely given. This is based on my understanding of
1 John 1:9. God knows our heart. If we do not want to do the in again or if we do not intend to do it again, He knows.