there are a lot of misinformation in 1hbh instructions out there. most coaches themselves are not confident how to hit a really good 1hbh. students will try their instruction and quickly feel lack of confidence in the method and will think 1hbh is something very difficult and not reliable. the flaws in swing path is rampant out there. should be able to shorten the swing around the contact point but rarely a coach understand these stuff. biomechanical understanding of 1hbh is in a sad state.
why not give out some of your pointers that you'd use when starting to teach 1hbh?