Years ago, my fish supplier would 'knock-out' the HSB with clove oil before stocking them into the pond. The 'sleeping' HSB would lay on the bottom until they woke up and slowly swam away.
These days, when I go and get HSB to bring to my pond, I don't use any clove oil. I just take a lot of time to ensure that the water temps are equal, and they they are gradually introduced to the pond water by slowly adding pond water to the transport water until you'd have mostly pond water.
I also use some kosher salt to help them along.
