Molasses and Honey with burned beef suggestions?

Bitter chocolate, lime juice, stock (chicken or beef doesn't matter), maybe a slosh of tequila. Cumin, a hot pepper of your favourite variety, perhaps some guava or agave? A little oregano, few cloves of garlic, a roughly chopped onion. Peppercorns--no salt, not at this stage.

Ensure enough liquid to just barely cover the meat, turn 'er on and leave 'er alone. When you get home, remove the meat from the pot, strain the liquid and set to reduce in a pot over high heat.

Shred the meat with forks while still warm--like making pulled pork. When the liquid is nicely reduced, add just enough to the shredded meat to keep it moist and luscious. Season at this stage, not before reduction. Eat in fajitas with, say, some nicely chopped avocado and buttery lettuce, maybe some pico de gallo.

I think that a crock pot won't help you at all.

There is no way to reverse what has happened and make it taste non-dry. You have 3 changing components in meat: 2 types of protein, and connective tissue. When the first type of protein denatures (at 50°C - we are speaking meat core temperature here, not oven temperature) the meat is medium. When the second type denatures (65°C), the meat is well done. The denatured proteins can't conatin moisture and it all leaks away, leaving the meat dry. This is the stage at which your roast has arrived.

What happens in a crock pot is that the third component - connective tissue - changes into gooey gelatine (starts at around 70°C, needs lots of time). So while the muscle fibres are dry, they are covered in the gelatine, and easy to chew. That tastes good. But it isn't the liquid in the crock pot which makes the meat tender.

The prerequisite for the third change is that you have enough connective tissue in the meat. Roast cuts definitely don't have it! In fact, if you had it, this reaction would already have happened in the oven. The simple fact that the roast which stayed too long in the oven is is dry is the hint that putting it into a crock pot won't make it better. Even if you let it swim in the nicest liquids, they won't get absorbed by the meat. Its physical structure is changed and it cannot keep liquids absorbed. More cooking won't help.

However, the situation is not hopeless. In fact, daniel already gave the solution. The taste of the dry meat isn't a problem; its texture is the problem. It is too dry to chew. As there is no way to lubricate the inside of the roast, you need to tear it into small pieces and lubricate it on the outside. I am not sure that "shred with forks" is the best way though (that's what would have worked on a brisket out of the crock pot), I'd suggest first cutting it into slices against the grain and then shredding (or maybe dicing) the slices. Then my preference would be to surve in a rich, lubricating sauce. I don't think that honey will help much for texture, but adding it for taste should function. Go for something with a very smooth texture - e.g. a bearnaise. This should counteract the dryness well. If you use something else as a sauce, try for a higher fat content. You may need to create an emulsion if you use a water based sauce (like the one daniel suggests).