I have started to put about 4/5 drops in my pony's water overnight. I rode him on saturday for the first time since starting them and he seemed to be much calmer. Whether that is my mind who knows!
Some years ago we picked up a new pony and were rather astonished to be given his bottle of Rescue Remedy by the seller. It should have been a 'warning' as he was barmy. I think we were the ones who needed the remedy or alcohol to cope with him,.
Rescue rememdy does work on animals. Two years ago I took on my gorgeous yellow labrador form a rescue charity The Labrador Lifeline Trust (excellent would highly recommend them). He found it hard to settle for the first 7 days so I rang the lady up who had placed him with us and she told me to get rescue remedy and put it in his water bowl. It worked and he was chilled out within a few days!!! I also have a chocolate girl and they share the same drinking bowl so she got some too and it did not have any adverse effects. I should imagine you would need to put quite a few drops into his bucket though. There are other calming supplements on the equine market.
I use it for my mare and me - we are both of a slightly worrisome nature!
I have a spray one rather than the drops. This is much easier to give to the horse - you can just spray it into the corner of their mouth. With either the spray or the drops you can drop a couple of drops / a couple of squirts onto your hand and just smooth it on to the horses nose / neck - this will work just as effectively.
I find the spray easier to give to myself if I am starting to panic somewhat - rather than having to faff with the drops.
I just use it when I feel we need it - rather than all the time - but if you have a streefull few days coming up it might be worth using for a few days - but I don't think it is something that I would use long term.