An excellent awareness article by USA Today … Bacteria, viruses, and other germs can accumulate over time for smartphones, as noted in this awareness article on need to clean items where there is constant daily contact

https://www.usatoday.com/story/tech/2019/02/26/your-smartphone-screen-probably-disgusting-heres-how-clean/2950106002/

Apple advises against using liquids or disinfectants on its devices. Instead, the iPhone maker offers a detailed list of how to clean your phone depending on the model that you have.  Motorola suggests using a microfiber cloth — the kind you might clean your glasses with — with a little water.

There are other ways you can safely clean your device depending on the type of phone you have. You may need the following materials:

  1. Microfiber cloth
  2. Isopropyl rubbing alcohol
  3. Water
  4. Cotton swabs
  5. Cleaning gloves