Error message "accessory not supported" when inserting earphones

Today when I inserted my corded Apple earphones into my iPhone, I got a message saying "accessory not supported." I used the spray dust and lint remover several times and also turned the phone off and on several times, but the error message still shows up. I connected my phone to a charge cord, and it works—no error message. I also inserted an adapter I needed when I was using older model earphones, and there was no error message with that device either. Maybe this just means I need to get new earphones! Although help articles about this issue suggest using a toothpick to clean the port, I'm reluctant to try that for fear that I might cause damage. Besides, if the problem is only the earphones, not the port, I can try another pair (I also use wireless earphones but prefer the small earphones under certain circumstances). If the problem occurs with new earphones, what's the best course of action?