So Alex told me about a trick to revive old bass strings. Apparently, part of the reason why they sound 'dead' after a while is due to all the gunk that gets caught in between the windings of the outer layer. Therefore, cooking them in water can help! (Obviously it doesn't change how the material itself wears out).
After boiling it in water for a while, and adding a dash of assorted spices, drying it out and restringing, it made a very significant difference in the sound (Not quite new, but much closer to new than before!)