I don't think you can test a DSP outside of its eco-system.... it will need life support, needs to be thought what to do, have it's senses tickled and have the ability to express itself...
If it's a 57070, it will run. at least if you can do the swap correctly. that alone requires dedicated solder skills....
not to the possibility of them to be Chinese made, i doubt that strongly. it's not like the OP627 rip off scam with a regular one hung low opamp rebadged you find else were on the net... this is a much more complex chip with unique I/O, power pins distributed and so replacing it with a 'compatible' chip is not an option. and reverse engineering a chip that complex just to sell a few to guitar players, I doubt it...
- Michael