Jet A1
I think you are a little out of line here. The most frequent use of this helpful aside is in North American airspace where I have heard it for the 5 years I have been operating there. Next is the Eurozone where our freunden in LH are always ready to help out.
Remember that although you can hear the garbling through your airband scanner, the poor ATCO can't - thus the quick "Blocked" promts him/her to re-transmit.
It's a safety thing..........