So I was curious... and did a little digging.
They seem to change based on the day of the week, similar to how the new Crescent hill daily they hide in different spots, and unless it's a huge coincidence, I believe their spots correspond to days of the week, and if not, they do at least change every day.
I picked up a lot of each bottle message and none changed it's own description.
Anyone else who wants to contribute, go ahead
P.S: You can get two at once as it happened to me, but I think it's very rare
(I messed up. This is the actual author/first post 
Dat Gallbladder
