I recall when I was a kid, accidentally discovering this little gem of a bug during a fight with the giant monster on the deserted island to the north east of the continent (maybe someone can help with the name of that mob?). I looked through the bestiary on here but didn't find it.

At the time, I didn't think of this as a bug though, as it gave me an unlimited supply of **every item in the game, so I thought I had found the developers Easter egg or something. There were so many of each item, it didn't show numbers, instead most items just had symbols to represent the amount (like hearts, diamonds & jagged lines etc). I obtained quite a few **really rare items, that I was never able to find naturally playing through the game.

Dunno if using Relm on that particular monster makes any difference, but you might give it a try.