The rookie congresswoman had her first experience with the food-shredding machine at her new Washington D.C. apartment Monday night and had no idea what to make of it ... other than it sounds scary.

AOC's reactions to testing out her disposal are pretty amusing, and to be honest ... she asks some fair questions about the benefits of the inner sink contraption. For instance -- is cramming food scraps down there really better than just tossing them in the trash?

Of course, the Green New Deal advocate couldn't resist getting political about discovering her newfound amenity ... and reminding everyone where she came from. She also cracked a joke about folks telling her to stick her hand in.

We don't suggest that, but here's a free hot tip -- if it starts to stink down there, drop a few pieces of orange peel in and flip the switch while running cold water.