Question:
Is it possible to use polycarbonate cups to drink milk but also to drink pareve drinks with a meat meal?
Answer:
I am not familiar with polycarbonate cups, and how well they clean. Even if the milk was cold, there will still be an issue here of leftover residue from the milk. Although it is possible, it is not a correct thing to do, because eventually there will be a time that the cup is not washed out well, either from the meat of the meat meal, or the milk that was poured into it.