A ring of revelation gives an oracle a revelation which they qualify for; extra revelation is a feat the same way extra discovery is. You'd need to be a 10th level alchemist to use an equivalent item and it'd cost on the order of 16K.
Or, you could look at spells with similar abilities - simulacrum, project image, bilocation, clone etc., depending on what exactly you want to do. Those are high level spells and permanent items containing them will be very expensive, but you wouldn't need to be an alchemist necessarily.