Nevski,
I followed the link you offered, and read the article by Archmandrite Ambrosius.
His Grace frequently refers to the following article, among other sources, as a means of explaining the practice and views of the OCA. The reference to St. Basil is most important in it. I expect few here will find the article satisfactory, but I think it nevertheless affords some needed clarity to this discussion, and with it, I am done with this particular exchange:
It is profoundly unsatisfactory, because it mixes a great deal of truth (discussion of long standing Russian practice, though with a great deal of ommission regarding Greek practice, and the practice of the early Church) with some very subtle, poisonous error.
From the article...
Each of the Orthodox Church’s mysteries has a dogmatic side. Forms may change and the canons may be amended, but their dogmatic aspects remains immutable, For example, the forms of the Divine Liturgy changed during the course of centuries, but the dogmatic essence of the Divine Liturgy remained and remains without change namely, that under the appearance of bread and wine we receive the True Body and Blood of Christ, which change takes place through the sacred action of the bishop or the priest.
Satisfactory explanation so far (though as will be seen, non-sequitor).
Thus, in the mystery of baptism its dogmatic foundation, its substance is that it is performed by triple immersion (or by its equivalent) pronouncing each of the Persons of the Divine Trinity, individually, and then — in the non-repetition of this mystery, since it was the spiritual birth of the Christian into eternal life in Christ. Just as our birth in the flesh occurs only once, so does our spiritual birth occurs only once in the mystery of baptism. This non-repetition of valid baptism, as a dogma, is sealed for all times in the Symbol of Faith: "I believe . . . in one Baptism." Even if the baptism was performed in a non-Orthodox church, but in the same form as it is performed among the Orthodox, it is accepted, according to the canons of the Ecumenical Councils. The Blessed Augustine wrote that the sacrament of baptism was instituted by our Lord Jesus Christ Himself, and even the perversion (perversitas) of the heretics does not deprive that sacrament of its veracity and validity. Thus it follows that re-baptism violates the dogmatic principle of the non-repetition of baptism.
(emphasis in the above is mine)
Some observations.
1) This manifestly contradicts what both you, and apparently (from your quotation) what bishop Tikhon said - it is a clear affirmation of the remission of sins/rebirth in grace being present in heterodox baptisms. The good Archmandrite would be well advised to read St.Cyprian, re-read the Canons of St.Basil (which outright say in the first canon that the communication of the Holy Spirit does not exist in schisms), and the Apostolic Canons which teach exactly the opposite of what he's teaching on this subject. For while they do teach that repeating a genuine Baptism is blasphey, they also teach...
Canon XLVI.
We ordain that a bishop, or presbyter, who has admitted the baptism or sacrifice of heretics, be deposed. For what concord hath Christ with Belial, or what part hath a believer with an infidel?
Even the canon reflecting the doctrine that repetition of a true baptism is sacreligious, is only half referenced, so to speak, in his form of thought. For example, here would be the form of the canon if it was agreeable to the Archmandrite's way of thinking...
Canon XLVII.
Let a bishop or presbyter who shall baptize again one who has rightly received baptism, ... be deposed, as despising the cross and death of the Lord...
Now, if that's all it said, he might have a point (though the previous canon would also have to evaporate, as would any other testimony on this topic.) However, this is the canon in full...
Canon XLVII.
Let a bishop or presbyter who shall baptize again one who has rightly received baptism, or who shall not baptize one who has been polluted by the ungodly, be deposed, as despising the cross and death of the Lord, and not making a distinction between the true priests and the false.
(btw., to be clear, I am not imply at all that the Archmandrite quoted this passage incompletly - rather, I am saying quite unequivocally, that his teaching that repeating a "true baptism" is sacreligious, while itself correct, cannot be applied to heterodox baptisms.)
2) It does precisely why I warned about previously - in supporting a false idea about sacramental economy (in reality, this is not economy at all!), it is in fact, round aboutly (and rather back-handedly) outright condemning the practice of receiving converts from heterodoxy via exactitude.
There is no "economy" in accepting a genuine Baptism. This is an abuse of terminology, and confirms precisely what others (and myself) have been saying in this forum.
But of course, I'm sure you will inform us that the above is not an "official statement" of the OCA... 
This reminds me of how Papists, to get around some of the more outrageous activities and teachings of some of their Popes, will say "well, it wasn't ex cathedra". Organically, ontologically, but not "officially" (whatever this means), a heretic.
Seraphim
