Hi,
first of all the screw thread in the oil pan has the same lead and diameter as a spark plug with 14mm x 1,25mm, e.g. NGK B-8HS. Any NGK
B-xyz will do. Try to get one and check that it works.
Once found you can tell the mechanician your looking for a spark plug heli coil. He must know then!
BUT I'd prefer to get a new pan and I will try to explain why:
If you move your little finger in the pan's hole you will notice a long winding of approximately 1 cm. This "tower", extending in the pan, would avoid the running down of ALL the oil in the pan. In addition all the mud and disposal would stay where it shouldn't. To get out of the trap our beloved little Japanese engineers cut a slot into the "tower" from top to bottom.
Means
a) the real winding's thickness is approximately 3mm ( the pan's wall thickness) which is the reason why you can easily crash it without a torque wrench.
b) the heli coil will cover the slot a bit so mud and disposal cannot get off the pan as easy as before
To make a long story short:
Try the heli coil way but don't get upset if the 3rd or 4th or... oil change will show up leaking again.
And - at last - another suggestion on your heli coil trip:
When done put the screw in again, fill about 4 liter of
used oil in the motor and bleed it again. Should take all crumbs off then and costs 0 $
Hope I could help
D1