Here's an easy solution for keeping your HDMI ports free from dust and other unsavory particulates. These squishy Silicone HDMI Dust Cover Inserts slip neatly into any computer or device with an HDMI socket, from the HDMI to USB-C Video Capture Adapter to the Raspberry Pi 3 B+. 

Comes in a pack of ten, so you're set even if you have a display or computer with a lot of HDMI ports, or if you lose some.