As an aside, our Zwartbles tups are mahoosive, and basically un-tippable except by a trained wrestler or Judo champion. One thing I've discovered is that when you're checking feet as you would a horse, they struggle less if you can support their weight on one of your knees, so they're not off balance. It works best for the front feet, but does also help for the back, if you can get somebody else to hold or distract the front end at the same time.
That said, the first couple of years we had them, we were checking and spraying feet all the time for scald. However, since footvaxing a year ago, we've had no further foot infections in either ewes or lambs. It's not a pleasant drug to administer, but I rate it as one of the best shepherding decisions we have made.