Is this technically a trick at all if you are just following the directions on the box? I’d say it is if following the directions is not the standard way of operating. If you feel a little dumb for not noticing those handy little push tabs that are clearly marked on the boxes, don’t worry.
You are not alone. Most people don’t notice them and feel just as silly for not noticing when the tabs are pointed out to them. It’s not exactly our fault really. There are so many labels and slogans on those boxes nowadays people tend to tune them out.