first I would want to know why they are acting sluggish and in what way? Whats their temp? how are their eyelids? are they pink or pale/white in color?
Goat drench is like nutri drench and is a vitamin & mineral supplement. Its not really just to give them energy. I give it to goats who are sickly or need an extra boost. But I also treat the reason for them being sickly along with the nutri drench/goat drench.
For drenching...you can take a syringe (no needle), get the right amount, and put it in the back of the mouth. But I agree with Stacey. You need to get to the root of the problem. If they're acting sluggish...could be anything from a worm overload to being overheated. The nutridrench or power punch will only help give them a boost...it won't solve the problem.