I use a large needle to break mine, but I've yet to get them even remotely even. I have very small hatches, I'm giving no where near the 500 doses that 1/4 of a bottle would treat, more like 25-50, and I only use as much dilutant as I need for the number of doses I'm doing, so they
should be getting plenty, and knock on wood so far it seems to be working. It would be a huge help if they'd just sell the vaccine w/o the dilutant. That's what makes this particular vaccine so expensive, the cost of shipping that gargantuan bottle (the last couple time I bought from Twin City, it's come in bags, that's a little better), and I always throw out half of it.
That said, I agree with you, Clare. It's a matter of getting people to
use the vaccine, and the simpler they make it, the more people will use it. And it seems like it would be profitable to the company, since they'll charge 1/2 the price for 1/4 of the dose. But the mentality is if you don't have 2000 birds, you aren't a "real" poultry operation and you're not worth their time.