From Rituale Romanum about the preparation and introductory rites to the blessing of baptismal water: “Tum Sacerdos cum suis Clericis, vel etiam aliis Presbyteris (…)”
Throughout the rite, there is only (and very specific) mention of priests. Remember that while the faculties of a deacon to baptize under ordinary circumstances is given through law, who can bless what is stated in De Benedictionibus for the newer blessings. In the same way, it is reasonable to believe that instructions regarding blessings in the Rituale are still in place, unless specifically said otherwise by Rome.
There’s more commentary here (I don’t exactly like this blog, but it has sound liturgical commentary, for the most part): wdtprs.com/blog/2011/03/quaeritur-deacons-and-blessings-with-the-traditional-roman-ritual/
I’ve never found where this statement is worded in that way, except for the simple fact that there were no permanent deacons present when these pre-Vat II rituals were used.
Still there were deacons, and they were allowed to baptize on specific occasions, but could not bless and exorcize water and salt.
In addition, remember that there were permanent deacons up until sometime in the 20th century, albeit very rare. The EF is older than that.
What is the specific difference in the baptismal exorcism, exorcism of water and salt in the EF blessing, and/or the blessing of sacramentals like the Benedictine medals which can be blessed with the ritual proper to them by any validly ordained priest or deacon?
I have no good answer for that, but I’m sure there is one, since the baptismal exorcism only required the Minor Order of Exorcist, while the exorcism of water and salt is reserved to priests, even when deacons baptized.
To say that the deacon cannot use the EF blessing of water and salt but he can in the new, all of which are taking place in the here and now with the authority granted now to the ordained, you are saying that the result of the two blessings are not equal. The result of the EF blessing is different than the result of the modern form of blessing of salt and water. That makes no more sense than the point made of a valid baptism or an invalid baptism dependent upon the form, EF or not, and whether a deacon or a priest performed the baptism.
A blessing does what it proclaims to do in the text. The two rituals say different things. Holy Water is not a sacrament, so there is no heresy in saying there is a difference between Holy Water blessed in the new rite and the old. Neither is it absurd.
For that reason, there is also nothing wrong about refusing to use Holy Water blessed in the new form when baptizing in the older form. It wouldn’t even be to disapprove of the “new” water; they are both blessed, but differently. And the Roman Ritual describes what blessing to use very specifically, so using baptismal water blessed in the new form would actually be violation of the rubrics. However, refusing to mix Hosts from the two forms when distributing Communion during EF Mass would be heretical; there is no difference between the two, since the Sacrament is the same.
Seeing blessings that say completely different things as different simply can’t be compared to saying the Sacrament as such is different or invalid due to the different form. In addition, changing the formula of Baptism would invalidate it. On the other hand, changing the content of a blessing (as long as it still constitutes a blessing) would not invalidate it, the item (or water) would still be blessed, but differently. There is a reason we use different blessings for different things.
Again, I’ll stick with my Judicial Vicar and my Bishop.
As a deacon, you are obviously in the clear as long as your Judicial Vicar and Bishop give permission, but to be honest, when dealing with the EF, I would, despite being a mere lay person (however with a degree in Theology, but still), recommend following the liturgical books to the letter except where Rome has specified something different (like the fact that all deacons can baptize as ordinary ministers). All come all, they liturgical books and Rome are the authority here, and the older liturgy doesn’t have as many openings for “local custom” and “pastoral considerations” as the newer one does.
(Lastly, I’m sorry if this seems arrogant - it is not my intention. I’m simply stating my view, which has been formed especially through seeing how important it is for any priest or deacon to stick to the books when it comes to the EF, or OF for that matter.)