Ask HN: Separating Two Glass Containers

Hi HN community! My friend has an interesting problem and I am hoping some engineering / hacking ingenuity can help. She has two glass containers stuck together, one inside the other, see here: https://ibb.co/5hwDR8P.

She has tried all kinds of things including: trying to separate them inside a water bath, greasing them, creating a temperature differential (ice on top, warm bath on the bottom), and even using WD-40. Nothing helped.

Any suggestions?