Yes, I have used Bach Flower Essences with success. One of my guys 'requested' -- via an animal communicator -- that I start adding two different Bach Flower Essesces to his food. One was Heather: to help him not be quite so self-absorbed and chatty all the time. The other was Chicory: for separation anxiety. It took 10-14 days, or so, before I noticed a real difference, but it did work and continued to get better!
So, stick with it... a few drops in their water or their food is all that is needed per day.
On a side note, my other cat -- a notorious cord chewer -- told this same communicator that he knew of a "tan powder" that could help him stop chewing cords. The communicator told me she got the impression it was a vitamin or something because the sensation she received from my cat was a mixture that had been ground up and it smelled... well, not good.
After a good six-months of off-and-on searching the internet to try and figure out what the heck my little guy meant by "tan powder"... I found it!!!! It's called 'Doc Ackerman's No Chew Formula.' It is a combination of several herbal ingredients and, yes, it is a powder and it is tan in color!!!!!! I ordered it immediately (I think with shipping and all for me it was about $15-$16, which lasts a long time). Similar to the Bach Flower Essences, it took about two weeks or so to begin noticing a difference. After a month, we could tell a HUGE difference!!!!! As long as we keep adding 1/2 tsp. per meal to his food, we're virtually chew free!!! Just an FYI...