Personally I carry a 4-leaf mandy bud, wild rarab tail, and lucky egg (if I have one,Ii ate the last one I had doing bcnm) whenever I am Farming, Logging (or any of the HELM activities), Camping a NM, Doing a BCNM, or Crafting.
Does it make a difference? I don't really know, but it might, and that is good enough for me. I mean, no reason not to carry them around for these kinds of activities right? I can say that my hatchet break rate is low, my hq rate is good, and I saw erase + utseimi: ni drop out of the same chest doing mandy bcnm (though it wasn't my orb >_<) when carrying these items. Is it coincidence? It certainly seems to be, but it might not be.
edit: Just thought I would add this.
If you really want to know, get a parser. Turn it on and do SEVERAL long farming runs both with and without the items. Ideally these runs would also be done under similar conditions such as moon phase and location. If you do enough of them then you will probably see either a trend form or virtual randomness. While this evidence is not conclusive, it can certainly make compelling arguments.
---> begin random conjecture <---
If there is anything to it at all, then I would guess these items lower the threshold for item drop. If every time you killed a mob a random number (0-999) was generated for all possible drops, then each drop was evaluated on it's rarity.
So, kill a mandy in the canyon:
2-leaf bud threshold: 700
earth crystal threshold: 200
saruta cotton threshold: 800
let's say you kill one and the drop number is 650. You would get only an earth crystal. Now let's say that each "lucky" item reduces the threshold (or increases the drop number) by 50. If you were carrying three lucky items, your effective drop number would increase to 800 and you would get all the items.
Is this how it is actually implemented? I'm willing to bet a large amount of money that it is not. However, if the "lucky" factor exists at all, then I would imagine that it is in some way implemented similar to this.
Edited, Wed Feb 23 15:53:29 2005 by Idwa