Who knows Bach blossoms?

My Gizmo always gets terrified when she has to go to the vet, she even has panick-attacks and starts to hyperventilate! When we return from the vet, she's not herself for more than a week ( quiet, not playing..)
Now i've heard of something called "Bach blossoms" ( someone i know from a dutch catforum gives it to her showcats) and it's also good for people ( my aunt gives it to her grandchildren)
Now u've all kind of sorts in those blossems, depends on the problem!
I gave Gizmo 'Rescue remedy' there 5 sorts of blossoms in here: for impatience, panickattacks, visits to the vet, to have innerpeace,...
Gizmo has to go to the vet on wednesday, i started to give her the drops 1 time a day since saturday, but i'm not sure if it works...i haven't noticed anything different about her and the girl from the store said that it would work immediatly? So now i'm wondering if there's someone who's also used this before?