I have had to use ether in my Cummins and heavy equipment. The right way is to crank the engine over then add a spritz to the air cleaner while the motor is spinning at full speed. If you spray first before cranking some say it concentrates in the intake and can just go into 1 cylinder, then can hurt the piston sometimes called ether lock. I have seen ether damage on a tear down of a Case motor, and they have factory ether injection systems. Ether is easially detonated and can preignite while the pistion is in the compression cycle ie before TDC. A trick was to use a thin plastic tube like vacuum tubing into the air cleaner and bring the ether can into the car so you can add a tiny amount while cranking. LOL but the heat gun way sounds easier.
heat guns a good idea... I still haven't put int my new glow plugs... I went to start the car this afternoon and it fired right up.... no GPs.. and it was stone cold... the difference has to be ambient air temp. yesterday morning it was about 50ish and I could t get it to start... today it cranked right up and it was about 75 out.. ...interesting...