One customer talk made me drop my bleed kit method

I always bled Shimano brakes with the cup attached and a slow funnel fill, until a roadie at the shop in Austin said his caliper kept dragging even after three bleeds. He showed me how air was trapped at the lever banjo because I was tapping the hose instead of rotating the bars fully side to side. I tried his trick on a 2019 SLX setup and the lever felt solid on the first pull, no bubbles at all. Now I swing the bars through the full steering arc during the bleed and tap the caliper with a plastic mallet. It only adds two minutes but saves me from doing the job twice, which is worth more than the $18 bleed kit I nearly replaced. Anyone else found a small technique tweak that changed how you service a whole brake system?