Even better - attribute a meaning, in that language, to refusing to say anything to the next person (remaining silent). Then you can put the summation of everything they know and everything you know into the case where you don't say anything (in that language).

This is similar to making a version of gcc that outputs a Tetris program everytime it's asked to compile a 0-byte file, or maybe outputs all of Wikipedia. I mean, sure, you can hide Tetris, or the whole of human knowledge, in 0 bytes this way. But it's not a very useful exercise.