Lowe's Home Improvement
5611 Buckeystown Pike, Frederick, MD
100% positive
Directions: By the end of the ceiling fan aisle that's closest to the registers. You'll see a sign for bathrooms that leads into a little hallway. If you go in, the gender-neutral bathroom is all the way on the left. Alternately, ask a sales associate for help finding the "family bathroom" (or just the restrooms, it's right with the others!)
Comments: no special hoops to jump through like asking for a key or being a paying customer! Just go for it.