Venial sins can be forgiven in many ways…(prayer, acts of love, reading scripture etc) including in the reception of Holy Communion (one though is exhorted to confess at least some…)
1394 As bodily nourishment restores lost strength, so the Eucharist strengthens our charity, which tends to be weakened in daily life; and this living charity wipes away venial sins.
1437 Reading Sacred Scripture, praying the Liturgy of the Hours and the Our Father - every sincere act of worship or devotion revives the spirit of conversion and repentance within us and contributes to the forgiveness of our sins.
The temporal effects may or may not be removed…
such can be removed in various ways…prayer, penance, the Sacraments, Indulgences…