You can mathematically prove atop Shannon's theorem that if the system can transmit comprehensible text information between two users, it can transmit binaries. Worst-case scenario, the users could use the text information layer to just say 'one, zero, one, one, zero, one' at each other, etc.

(Socially banning them can certainly "work," in the same sense that social banning works in any context: pushes it underground out of the moderators' lines of sight. Depending on what you're trying to accomplish, that can be good enough).