iPhone Accessory Not Optimized Fix

This morning I woke up seeing my iPhone turning on and off, as if I got some messages coming in every minute. And this notification appeared instead:

This Accessory is Not Optimized for this iPhone

You may experience noise caused by cellular interference and a decreased in cellular signal strength.

I was like WTH? I didn't add any new accessory or app to the iPhone recently. So here's a quick fix on how to clean and clear the problem.

Step 1: Undock the iPhone if it's still docked.
Step 2: Look at the iPhone's charger outlet (at the bottom of the only physical button)
Step 3: Fork out the lint, dust, dirt etc inside the outlet with a toothpick.
Step 4: Use cotton or twisted tissue to clean the remaining dust.
Step 5: Gently blow the iPhone's outlet.

Step 6: (Optional) Bang the iPhone on the table to unstuck whatever is lodged in the outlet.

There. That should stop the message from popping out. If problem persists contact your retailer.