I didn't read the original thread but I think you've found what his real problem is.

If a guy masturbates the same way all the time he can train himself to only orgasm one way. I doubt the cock ring would help much but you can try it. I say it won't help because even with the cock ring your vagina won't feel like his hand.

He needs to change his method of masturbation and retrain his body to accept different stimulation.