It is a subliminal made of separate sounds. It starts out as a sentence, which is the one in the lyrics and with the addition of a myriad of whoops and partial words, that when mixed come out sounding like "everybody smoke pot". When done in this manner the censors can not find the words even if they take every single track and try to find those particular words. No one person knows what the sound they are making is going to be mixed to sound like. No one can testify or rat you out as they don't know. They are like when a company makes something and they don't want the companies engineering the parts to be able to steal the thing before it is patented then you get just those parts for assembly into a final product. A really sneaky way to avoid detection and not get banned in the process. Lennon was a really smart guy. As was George Martin. When asked they had deniability. Also as the sound repeats itself they decompose it back to it's primary parts again. Nice trick.