I saw a post on Facebook saying that a magga-phala lābhī / noble disciple would never knowingly drink alcohol, and that even if alcohol was mixed with milk and put into their mouth, only the milk would go in and not the alcohol.
The post mentioned this as an Atthakathā explanation, similar to how a swan separates milk from water.
“..noble disciple would never knowingly drink alcohol, and that even if alcohol was mixed with milk and put into their mouth, only the milk would go in and not the alcohol.”
No. That is laughable.
When attaining magga phala, it is the mind that gets purified. The physical body does not suddenly develop a filter to filter out alcohol!