Your work reminds me of what I did on my 69 20 yrs ago. Blasting the underside with side curtains to contain the MEDIA and dust brings back memories. I was able to collect most of the media and reuse it by straining through a hunk of window screen.
Good to see you working with your son, more memories, and that he's wearing his PPE but.......open-toed shoes?
C'mon Dude!! This is no time to be taking a kid to the ER!