There's only hope in sustained and repeated practice.
You can teach an average pilot to safely barrel roll the simulator
on instruments after 3-4 attempts. That is an unusual attitude. Freeze the simulator when inverted to discuss the use of the sky pointer for recovery. Pitch to 50 degrees or more nose up then teach the student how to unload and roll to the nearest horizon for recovery.
On instruments. it is all clearly described in the FCTM. It is nothing new. 2-4 attempts at very nose high attitude recovery should have the student recovering consistently well.
All on instruments.
Put simulator is steep spiral descent. Demo the correct recovery (unload and pull when wings level). Teach the correct method of correcting GPWS Pull Up warning. 3-4 attempts for a competent pilot
on instruments.
There must be a sensible limit to repeated practice. Like riding a bicycle you will never forget. In almost every case of airliners crashing due loss of control in cloud or at night, the blunt fact is the pilot concerned simply could not fly on instruments. The key to a successful recovery from an unusual attitude is good instrument flying ability in the first place.
If your whole career from cadet to captain (common nowadays) has been monitoring an automatic pilot, leaving only five minutes of (if the airline permits) manual flight with autothrottle engaged and concentrating on the flight director, then no wonder self confidence fades and you need the crutch of the automatics from take off to touch down.