To be honest, I don't think so.
I'm using calm agent on my horse, and I notice chammomile + vervain seem to be the best. Everything else is not very useful (and mix with garlic drove her crazy 2 times I tried it). AND you have to give those herbs for at least a week to see the effect. So for just a show your best bet would be those one-time tubes with paste (Quietex or whatever the name of it). BTW, don't rely much on those either - calming is a very individual thing and what works for one horse has no effect on another.