You are correct – they are rites, not sacraments. A sacrament is a visible sign of an invisible truth – it’s a tangible sign of God’s grace being given to us. Excommunication is certainly not a sacrament since it bars someone from the communion of believers – there is no grace in that. An exorcism is a casting out of demons or demonic possession – it’s not necessarily a grace received so much as an evil departing.