Is this similar to working under the table?
Yes, that is quite correct. Simply speaking, under cover. I was sure I wrote coatling
- płaszczyk - but now I see it is coating, still close but not what I really meant.
Ones of disorder and confusion?
Yes. Also chaos or even violence. I think Mexico
idiom comes from Kraków. Meksyk
was a bar in Nowa Huta District in communist times and it was infamous for rough customers, heavy drinking and frequent fighting. Saigon
bears an obvious reference to the Vietnam war.
I haven't heard either in a long time.
I come across them regularly in online comments.