Any way to include a full block (U+2588) character in the login banner of a Cisco Catalyst 3560?

I am trying to do something silly and superfluous with a giant ascii art banner. Specifically it breaks for me when I attempt to include the full block character or a few others.

The full block is interpreted incorrectly and becomes circumflex+full block like so:

This:

"█████╗"

Becomes This:

"â█â█â█â█â█â•╗"

Any workarounds?