Most of the jobs right now are artsy / techy because those people are easiest to reach from our personal networks and that's where we started signing up mentors. Feel free to throw a janitor in a suggestion box, we'll try to sign one up.
I don't know any janitors in poland. But think of the possibilities. You could offer a "Janitor's day in the life" to entitled tech workers. The tagline could be "Step outside your bubble and see how the rest of the world lives."
Brewer! Makes more sense than brewmaster. I assume that dealing with common aliases is on the todo-list. Just the ones for "police officer" could be pages long, and region-dependent.