Sacred snails

nice pics, i observed the same in my garden, and now got inspired to find out, "what's the benefit for the snail"?

I found a congregation of mature snails sheltering inside a TBM cluster. About a dozen or so cloistered away in there, asleep I reckon. They hadn't eaten that TBM much, if at all. So, at bare minimum, shelter is one thing the cactus affords. 

What did the collectors do with the snails?  Eat them or venerate them. Both?

"Even the snails are said to contain mescaline" -- same source as above