A few decades ago, I was a relatively young English teacher who had a class of sophomores in a remedial writing program. All students had poor punctuation skills. I taught them a concentrated, targeted, traditional series of lessons designed to solve that problem once and for all. At the end of weeks of concentrated effort, not a single student showed any improvement. Not one. I concluded they were incapable of learning punctuation.
About a decade later I found myself in exactly the same situation. Having learned my lesson, I completely abandoned that traditional approach and did something entirely different. Within about a week, every single student was proficient at punctuation. Every one. I concluded that the previous class had not learned punctuation despite all that time on task because my instructional methods sucked.
Decades ago, scuba instruction featured long, long lectures. This not only took a very long time, it was ineffective--student retention of information was poor. That gave way to home study followed by instructor review. This cut time considerably, but, more importantly, it greatly improved student retention of information. Now that approach is giving way to online instruction, which takes less class time and features even greater retention of information.
The idea that if it takes longer to do something, it must be better is one of the greatest fallacies in instruction.
In the case of this specific issue, what most readers don't know is that the poster above who talked about his practices has been inactive recently, but has a long, long history in this area, a history to which people are replying rather than that specific post.