Doubtful.
If an act of contrition is enough to place someone into a state of grace, then why would it not have the same effect if made before a person who was ordained?
I thought the SSPX considered the new rites as valid? or do you all reject everything from the post conciliar popes? Because if you do, then the church was reduced to a remnant and most clergy are imposters wearing a priest costume.
A
perfect act of contrition has the same effect as absolution in the confessional, but the whole point of confession is that perfect contrition is both difficult to come by, and it also can never be presumed. Perfect contrition is being sorry for your sins because of the offense levied against the Infinitely Perfect Creator, rather than fear for your own soul and the fires of Hell.
The SSPX in recent years appears to have become much less apprehensive about the new rites of ordination (another example of a clear break from the holy Archbishop) but there are definitely priests in the SSPX who have their doubts. And yes, the Church
has been reduced to a remnant and there are many doubtful priests.