don't run alcohol though a vacuum pump with the motor running.
compressed air + alcohol = engine or fire.
vacuum pump oil itself can smell horrible even without unknown stuff mixed in.
I don't mind tearing pumps apart, as long as I know what they were used for, or were rebuilt and came with fresh oil.
If you don't want to tear it apart, you could try flushing it and dumping in fresh vacuum pump oil and repeating.
I always get standard pump and difusion pump oil from kurt lesker company. They have incredible tech support, and can surely tell you more about your pump than you could find on the internet.