If you've listened to just one of Icke's talks you will know he appears to understand NLP and subliminals very well, as well as the frequencies generated by such things as words. He will also be aware of negatives generated by negative phrasing - such as DISOBEY. He should be getting people to focus on positive aspects, THINK, RETHINK, BE FREE, etc. He knows full well that a negative negative in language does not make a positive, it just makes an accumulated double negative, and instead of your word phrasing having power, your choice of negatively referencing someone else's phrases GIVES THEM all the power!
DISOBEY is still the same semantic family, and therefore the same NLP direction as OBEY. During the Iraq war (in the voice of Uncle Albert) I abandoned the Anti-War movement because I saw them as playing up to the war mongering parties - all their slogans were 'anti-' something, or against what other people were doing. I kept proposing POSITIVE ACTION - therefore we went under the slogan 'PEACE' as opposed to ANTI-WAR (actually, "Hands up for Peace"). On a subliminal level the semantics of negative still get home the original message, because you have to refer to the original message to negative it! Being 'Anti-war' means that you must exist in the shadow of the war brigade and highlight and focus on everything they do in order to do the opposite! Being all about Peace means you can ignore them entirely and do your own thing!
In order to DISOBEY, one must first OBEY, or at least work to the concept of obeying to then find its opposite. To truly go against that term you must IGNORE IT and use a positive opposite term - so he should go with a slogan like BE FREE, RETHINK, THINK FOR YOURSELF.
That Ickers fail to spot these things; hasn't he given them enough lessons in how to spot subliminals in his talks, is nothing rubbing off on these people?
That those chairs are designed so that only the word OBEY is displayed is simply

happening in Ickes own realm, when he puts himself out as a champion of spotting and dealing with subliminals! Was that just too subtle? Oh dear!