Dear Robert:

Waste of time? Hardly. This is a very good question.

The short answer is "no", the baptism of John was not efficacious in grace, it did not confer grace.

The Council of Trent infallibly declared: If anyone shall say that the baptism of John has the same force as the baptism of Chirst let him be anathema (Canons on the Sacrament of Baptism; can 1)

Thus we know for certain that the baptisms of John does not have the efficaciousness of the baptism of Chirst.

Here is the teaching of St. Thomas Aquinas in the Summa:

The baptism of John was intended by God to last only for a short time...

...the whole teaching and work of John was in preparation for Christ: just as it is the duty of the servant and of the under-craftsman to prepare the matter for the form which is accomplished by the head-craftsman. Now grace was to be conferred on men through Christ, according to John 1:17: "Grace and truth came through Jesus Christ." Therefore the baptism of John did not confer grace, but only prepared the way for grace; and this in three ways: first, by John's teaching, which led men to faith in Christ; secondly, by accustoming men to the rite of Christ's baptism; thirdly, by penance, preparing men to receive the effect of Christ's baptism.

...the baptism of John the body alone was cleansed by the water. 

... In these words, as Bede says (on Mk. 1:4), a twofold baptism of penance may be understood. one is that which John conferred by baptizing, which is called "a baptism of penance," etc., by reason of its inducing men to do penance, and of its being a kind of protestation by which men avowed their purpose of doing penance. The other is the baptism of Christ, by which sins are remitted, and which John could not give, but only preach, saying: "He will baptize you in the Holy Ghost."

Or it may be said that he preached the "baptism of penance," i.e. which induced men to do penance, which penance leads men on to "the remission of sins."

Or again, it may be said with Jerome [Another author on Mk. 1 (inter op. Hier.)] that "by the baptism of Christ grace is given, by which sins are remitted gratis; and that what is accomplished by the bridegroom is begun by the bridesman," i.e. by John. Consequently it is said that "he baptized and preached the baptism of penance unto remission of sins," not as though he accomplished this himself, but because he began it by preparing the way for it.

God Bless,
Bro. Ignatius