those feet have been washing up for 20 years

https://604now.com/wp-content/uploads/2016/04/leg-in-boot-street-vancouver.png This street in Vancouver is from a case in 1887.

Here he connects the dots

Dots that only he can see. The cause its a human body decomposing in nearby waters while wearing running shoes. As the body decomposes the feet break off at the ankle, especially if the exposed leg is eaten by sea life. Hands tend to do break off as well. And why aren't they finding hands? Because running shoes act like flotation device and also protect the foot from predators. And the place where these feet are found is where the current is that part of the Pacific wind up.

They actually did a study in 2016 to fine out what happens to a body in these waters. To substitute for a body they used pig carcasses.

In the spring, the carcasses were completely reduced to the skeleton in just four days; in the fall, the process took just three. The bodies were visited by sharks, spot shrimp, and a giant pacific octopus. Within minutes, amphipods had settled upon the bodies, eating the internal organs and tissue first before moving on to the skin