That advice from Crowley was based and didn't mean this.

It was to deprogram autonomous routines, like walking or reading backwards.

That then he was a fag otherwise who worked for the crown as spy to access higher level knowledge for himself is pretty known, Giordano Bruno did a similar thing with the church. Although Bruno later quitted after finding out what he wanted, while Crowley preferred to go along with it until death not to end a traitor like Bruno. One went for truth and the other was happy with power.

Still, that advice isn't any bad as part of a 'magical' training process.