I know of a number of reverse commuters to Quantico, Ashburn, and Annapolis from DC, and Baltimore is not much farther and has better transit options.

First, is it worth it? Baltimore is not necessarily bad, though it is noticeably different from DC. DC is more transient, nerdier, more sophisticated (and more pretentious). Baltimore has local character, down-to-earth people and venues, and much lower rents. I would probably rather live in Baltimore than in St. Louis, Sacramento, or Milwaukee… but I would rather live in DC than Baltimore. I will say that if you're interested in city life, pick one or the other. There is nothing in between but suburbia.

If your job offers a transit subsidy, getting a monthly MARC pass would make the commute possible. You'd need to get to Union Station in DC and from BWI or Penn Station in Baltimore, and that is the tricky part— Union Station is not in a residential area (and at the opposite end of city from Georgetown), so you'll need to walk, bike, bus, or Metro there. Penn Station, similarly, is not in downtown Baltimore, so you'll have an extra connection to make on that side.

Depending on your hours, driving might be possible, but keep in mind that they are not exactly twin cities; downtown-to-downtown is about 40 miles and with the only major corridors being I-95 or the Baltimore-Washington Parkway, traffic is atrocious. Even the reverse commute will not save you here, as there are many people driving out to jobs in Greenbelt and Fort Meade which lie in between.