You could probably work around the same-clothes-not-clean issue by doing what service techs that deal with the public do: Get a patch sewn onto the shirt with

You could probably work around the same-clothes-not-clean issue by doing what service techs that deal with the public do: Get a patch sewn onto the shirt with your name on it. People's minds are conditioned to think shirts with patches on them are uniforms. You don't even have to use your own name. Thrift stores will sometimes have uniforms for sale with name patches still on the shirt. Aside from being comfortable with the sticker price, you'd just have to be comfortable using some other guy's name patch on your shirt. For the record, I'd be cool with a patch that says "Peter Cooper".