lakemonster, I have a notion that the stories you hear like that, are simply superstition.
Where I live, in central coast CA, has had ..... for many decades now ... heavy immigrant population from Mexico (d/t the crops grown here, and the labor/jobs it creates). As such, I too have heard endless stories over the past 35+ yrs. of this hobby, whenever I'm out in the field detecting, and a 1st generation Mexican approaches me. They spin fabulous tales of buried treasure back in their hometowns "if only someone had a metal detector to find them". And all have stories of treasures found, that they know "first hand", blah blah blah. They're simply convinced the treasures lie in every old house's walls, every cave, etc....
So finally, in about 1994, I accepted the invitation of some of my Mexican employees to make a trek with them down to Mexico, to look for some of the treasures they were convinced was there. We went way up in to the Sierra Madres, in the state of Durango, where adobe homes that were 300 yrs. old line the street! (old conquistador mining villages, an entire day's drive on dirt roads back in to the wilderness to reach).
Once we were there, I had them point out all the various ruins they had spoken of in the United States, that were suspected/known to have treasures there. But one by one, as we hunted them and found nothing but junk, the stories began to un-ravel. What had been "coins I saw with my own eyes found in the floor of this ruins", became "well, I heard if from my uncle Juan, who saw it first hand. So we go talk to "uncle Juan" and find that he too simply heard it from others, and so forth. And as it always turned out, it was always "someone who told someone who told someone, who told someone, etc....." And before you know it, it's just taken as absolute fact.
And if you dare question them (call it superstition) you risk offending their machismo, or they write you off as a gringo who doesn't have a detector that goes deep enough.
So I think that 99% of the stories you hear from Mexico, are just cultural supstition. Sorry about that.
We didn't find any caches, but we did find individual coins dating back to the 1840's. The trash down there is unbelievable! The small towns have no curbside trash service like we are accustomed to here in the USA. Instead people just bury their trash in their back-yards, or take it down to the nearest cliff or river, and just dump it. So no matter how remote of a site we treked to, we encountered reams of trash.
Yes we would, please! 
