Turn it off before you go in there? Otherwise, no. Unfortunately, or fortunately depending on how you want to look at it, k-relay has classified any item that doesnt not contain a <Tier> node in its object's xml to be considered tier UT, and the code ranks tier UT to be the best (tier UT = tier 255). So in that sense, you could try to set the loothelper config to not loot anything with a tier less then 256, but it looks like all the tier settings in loothelper are only a byte so you cant set it to larger then 255.
So back to what i originally said, just turn it off before you go in. Or turn it off, drop the item, and turn it back on. OR set your loot speed to like 2000 (2 seconds) and then you can drop something and be far enough away that it wont try to loot it again. Those are the options pretty much.