Popular piety can be the bugaboo of academic theologians. We can always find some kind of doctrinal fault behind a common popular devotional practice, and therefore discourage or condemn. I think a better tack is to ask the question, what is motivating this person to engage in this devotion? Could it be an acute sense of a particular doctrine that leads to what we might consider "exaggeration" or "distortion."
A case in point is the pious practice of not chewing the Host at communion. Some theologians would argue that this is a sign that the communicant does not understand that the presence of the Son of God is sacramental, rather than biological. The communicant must be skittish because he considers it crude to "chomp" on the very flesh of the Son of God. They must not understand that chewing does not affect the "flesh" of the Son of God, which is the resurrected, spiritual flesh of Jesus made present sacramentally in the Consecrated host.
The theology of the critiques is all fine and good, but what is missing is a sensitivity to the other possible motives for this practice. Might not a communicant be skittish about "chomping" on the Host because he has a heightened sense of reality of the Incarnation, the real presence of the humanity of Christ in the Eucharist, and a real veneration for the God presence in the Eucharist? Might not these strongly felt sentiments be commendable, rather than condemnable, even if not strictly necessary for the theological reasons stated above?
I don't practice this particular pious reception of communion. I try not to crunch noticeably, however, which I find a distraction in others.