I don't generally read much any more about Zen Buddhism, but yesterday was different. I was emailing with Stuart Lachs, an occasional 'bad boy' writer in the world of Zen, a guy with enough solid practice to have street cred in my book, and he pointed me to an essay he had written on the hua-t'ou form of practice. Since I was only vaguely informed about hua-t'ou, I read and enjoyed it...and recommend it to those whose curiosity inclines them in that direction.
Stuart's other essays (Coming Down from the Zen Clouds: A Critique of the Current State of American Zen, for example) make a lot of Zen enthusiasts uneasy ... or, if not uneasy, then sometimes overly-enthusiastic. The questions he posits and the historical evidence he adduces often leaves the professional Zennies gasping with indignation or grasping for straws that will bolster the reputation of their professions. Seldom, that I have seen, do they meet Stuart on open ground, critiquing his critiques with historical or common-sensical counterargument. Instead, there is a retreat into 'spiritual' assertions or touchy-feely hand-wringing or blustering outrage that does not speak well of the Zen they have chosen to embrace.
Anyway, the hua-t'ou essay is not confrontational as far as I could see. It's just a description of the practice.