Is such an exorcism effective?

Exorcism was accomplished by the Lord Jesus in his own authority as “the Holy One of God,” and by his Apostles and disciples in his Name:

The seventy returned with joy, saying, ‘Lord, even the demons are subject to us in your name!’ And he said to them, ‘I saw Satan having fallen like lightning from heaven. Behold, I have given you authority… over all the power of the enemy… Nevertheless, do not rejoice that the spirits are subject to you, but rejoice that your names are written in heaven.’ (Luk 10:17–20)

As St Justin Martyr testifies:

We continually beseech God through Jesus Christ to preserve us from the demons… for when they are exorcised in the name of Jesus Christ, they are overcome; and thus it is shown to all that the Father has given him such great power that even the demons are subdued by his name. (St Justin Martyr, Second Apology, 6)