Grave Sucking

According to this article, it has also been called "grave soaking" or "mantle grabbing."  The idea is to lay prostrate on the surface above the grave of a holy person and soak up the spiritual power of that person as it leaks from that person's buried body.

The title of the article refers to this practice as "crazy," and its conclusion seems to reveal that the author is highly skeptical of the merits of the practice.  Yet, it is not obvious to me that practice is crazier than other religious practices such as praying, giving offerings, wearing religious tokens, or participating in other religious rites.  Grave sucking is less common that those other practices to be sure, but because a practice is less common or outside traditional practice does not imply that it is necessarily less valid.

However, perhaps the issue of credibility may be more subtle?  Do you think that a practice may be perceived as less credible because it is less common?  That is, is there some possible logical connection between the frequency with which a religious practice is undertaken and its credibility and efficacy?