Friends of mine have and I made up a similar spray. It is basically aromatherapy oils in water - all the calming ones like lavender and geranium, camomile and bergamot.
It's ok but very expensive at £19 a tiny little bottle. Personally I would buy a few of the 'relaxing calming oils' and soak a rag with a few drops of each and rub your hands on the rag before handling your horse - same effect
You can hang a rag soaked with these oils in the stable to help 'calm' a horse. It does work I am a trained aromatherapist and have enjoyed experimenting with oils with my horses. Caroline Ingraham has published an eye witness booklet:
I've used it on a variety of horses, and all of them have been calmer in comparison to before. Yes, it is pricey, but I use so little of it that it is money well spent IMO.