The research examined the effect of using touch to assist learners in making associations between new symbols and new sounds. While looking at the graphic form of a letter/symbol and saying or hearing the sound, subjects in the experimental group "explored" the form with their hands as well. The haptic effect was clear: " . . . the explication lies in the specific properties of the haptic sense . . . in the hands, which plays a "cementing" role between sight and hearing, favouring the connection between the senses."
What that helps explain is why using haptic anchors in fossilized pronunciation work should, indeed, assist learners in "replacing" sounds embedded in specific words more efficiently. Done haptically, that does not have to be an especially time consuming process. (See earlier posts on how that process is carried out.) For most advanced learners, de-fossilization is, unfortunately, a painstaking, one-word-at-a-time problem: a new sound has to be associated with the graphic representation of every problematic word, not just encouraged to generalize unattended out through the learner's interlanguage. In other words, just teaching the "fossilized" how to correctly articulate a sound in isolation is nearly pointless--unless every "misuse" is systematically ferreted out (Ready?) . . . manually, of course!