Today is 'sheep dip' day. We're a little late actually but this summer has been quite dry and we've been quite busy. On the farm I grew up on we used to have a thing like a swimming pool and a series of pens whereby sheep were tricked into getting alongside so my uncle could push them in. It was water, mostly, it had various evil chemicals to kill lice etc. The sheep almost certainly hated it. But they were definitely 'dipped'.
We only have four sheep so the swimming pool would be overkill (and it is not like we would want to use it ourselves after them). So we have a pour-on version of the same thing. First catch your sheep, then run a squirt of this stuff along their backs and around their rear end.
The 'catch your sheep' bit is the tricky part. We don't have a dog, that would make it easier. A well trained sheep dog is a marvel to watch. No, we just have Mrs & me.
What we do is chase them around the paddock, making them run as fast as we can, and eventually they get too tired and give up running. Then I take a flying jump at the sheep of choice and hold it down while Mrs applies the pour-on.
It helps they they are really unfit sheep. They basically sit about all day. It also helps that they are fairly tame so, while they don't like being handled they aren't particularly scared of us.
Now they are huddled down the far end of the paddock looking embarrassed about their blue backs and blue bottoms, and they will never take fruit from our hands again ever, until tomorrow.