How does drop rate accessory work when in a party

I'm not 100% sure but I think the drop rate only applies to the person dealing the last blow to the monster

Pretty sure this is the case with drop rate in general, unless it's a drop rate event. If someone has a coupon or anything else that affects drop rate, it only works off of their kill as far as I know. I know there's a lot of people who do this every day in their bossing so they'd be able to give better insight.