How to remove glue from ceiling
I would recommend that you reuse the furring.  Here is my reasoning


It's already there.
It will cost more to remove it than reuse it
It will provide space to run electrical, network, phone, coax, etc wiring
Unless you head height is really low, the 1.5" will not be missed too much.


Essentially, you have a 'service cavity'.  You can place low profile can lights, electrical wiring, etc in this space.  I'd keep it if it is secure.