Done both, in all honesty I think it depends what sort of sarcoids your horse has and how much their immune system is struggling. I think pretty much the Liverpool cream is the best, but if you back it up with Sarc-Ex you are supporting your horse from the inside as well.
Have you tried Faye at Pear Tree? Its behind the tip and I have heard really good things about the yard.
Not really many yards with good services and facilities in Glossop, I have given up and just travel instead to my horse now.