Hi everyone. Was just wondering if any of you guys have experience with Think Fly, the herbal supplement?

I've been adding it to my horse's feed since the beginning of February this year, and he had it all last summer until the fly season ended. But I'm not sure if it's actually making a blind bit of difference.

He suffers from sweet itch, and wears a Rambo fly buster rug, that's the one with the fly repellent in the fabric (supposedly.) But he still gets bitten. He has a mask on too when the flies are out in force. This year he's the most comfortable he's been in the last five summers, which I'm pleased about, but I think that's mostly due to the new anti-itch product I've been applying to any scabs/spots that come up.
I'm just not sure whether or not I'm wasting my money on the Think Fly. (Don't get me wrong, I wouldn't skimp when it comes to making sure he's cared for, but I don't have money to throw away.) I daren't take him off it in case it actually is doing some good.

So, does anyone think that Think Fly actually works?

Thanks in advance for any thoughts.