I just got some of Mann Lake's "Pro Health" (their version of HBH). 4 tsp in a quart of 1:1 syrup. A $7 pump up sprayer from Home Despot.
One hive went ballistic when I went to open up the entrance. I light spritz of PH syrup in the entrance laid them down like a miracle. I checked 8 hives, and used ~ 1 pint. A little in the entrance, and a little across the top bars.
Some do not recommend spraying syrup, but it has always worked well in my dry climate. From what I've read, I wouldn't recommend it in more humid climates.
This was Absolutely Amazing! From hot to cold, in seconds. ( I suspect that "hot" hive was queenless/superceding).
Much more effective than smoke, both short and long term.