I have not! I just chew shiso leaves every once in a while (friends in Philly have thriving pots of them), or have them in soup. I'm in Gaithersburg; I'd love to try shiso juice. I'd be happy to host you on my front porch /in my backyard, or come over (?), or meet somewhere (all masked).

when you have the shiso-infused water that's kind of a mellow dark red color, and then you pour in a little vinegar and it instantly turns the vivid bright red you see in that photo

Ooh!