Set up an experiment in research maybe? Get 100 enthusiastic people to live the word of the ETWOLD section on the critical question:

«Practice in attaining the critical-reflective frame of mind is only necessary in the beginning phase, which may last a
number of months. Later on, lucid dreams will occur even if the subject has not asked himself the critical
question during the day. The frequency of lucid dreams then depends to a large extent on the will of the
subject. Most subjects who consistently follow the above advice experience at least one lucid dream every night.»

Say they do this for six months. I'd be very very surprised if more than 30 percent are having LDs every night. If the route to having LDs every night was regularly asking the CC then there'd only need to be a couple of paragraphs written on LDs - not the scores of websites and books we have now. SLaB has to carefully choose his statistics to make LDing look easier than it really is or nobody would buy his books.