If it's a dog, it needs to be one that's wise to primitive sheep (and/or a handler that is, and a very obedient dog
) - you can't push them the way you can a less flighty type, they won't take 1/10th the pressure a commercial sheep will. And frankly, if they want to be away, they'll be away.
They need to feel safe, David - and it's going to take a little time...
Can you feed them a little in a trough every day? Get them more used to you being near them? And then cake them in the pen, etc...
Once you have 'em penned, get 'em penned
tight asap, so they don't have time and space to jump out. Drench them swiftly and confidently, do anything else you need, and let them out as soon as practicable.
It does get easier as they get more used to you, promise.
I mostly keep my new primitive-type sheep in a stable for a few days to a week, getting caked, hayed and watered twice a day, so they get used to me being a friendly provider. They don't get to be outside until they are relaxed about me being in the stable with them. Then, if poss, they go in the home paddock with some tame sheep, getting caked and witnessing the occasional random digestive biscuitting