I’ve got a single-cup pourover coffee thingy at work and use it with one of those cloth reusable coffee filters. To be honest, I worry about grossing out my co-workers (but apparently not enough to stop drinking pourover coffee at work).
Did you know that single-use coffee filters can actually be double-use? If you want to go a little bit greener (and halve your coffee filter budget), use each single-use coffee filter twice. After using it the first time, rinse it out just like a cloth coffee filter and dry it the same way. (I hang mine on one of the loopy things where you’re supposed to put drinking glasses). When it’s dry, or even before, you can use it for one more cup of coffee.
Don’t reuse it more than once or you’ll end up with a mess. Ask me how I know.