This situation needs investigation by CASA. If in fact the reports are correct, the CFI, Flight Examiner(s) who issued the FIRs, the instructors and their students need to undergo remedial training.
This technique is not only dangerous, it is not an accepted practice and contradicts the Flight Instructors Handbook guidance and the Part 61 MOS.
There is no need to pick up a wing during a stall, rudder is used to prevent yaw in the event of a wing drop and ailerons used to level the wings after recovery from the stall.