Having the intention to do what the Church does is manifested when one does what the Church does.
The Church baptizes by the minister of the sacrament pouring water on the head of the person being baptized whilst the minister recites the form of baptism.
If a person baptizes this way he manifests his intention to do what the Church does.
Question is, "Would there be an impediment on the part of the person
being baptized?" Hence, would original sin be cleansed? If not, should not the Sacrament be repeated using the
conditional formula -- "If you are not yet baptized, I baptize you..." or something to that effect.