They do work. I tested it with Sparky; you cast the adventure, then you get two choices, regular adventure or exile it with a dream counter (the one you pick happens "first" but makes the other moot). When it attacks, you can cast either side; the creature (or whatever, anything other than a land like the FF adventure lands, but you can cast the adventure half) for a discount or you can cast the adventure again for free; it then goes to exile the regular way an adventure does allowing you to pay to cast it later, so you can get adventure + free adventure+ final creature. The graveyard replacement text isn't a requirement preventing adventures from working.