here is a summary:

we identify successful viral cultures when we take a sample from an sick person and put it in a dish of cells and see those cells burst. the cells that are originally "virus" free were grown in a nutrient rich medium.

at the point of inoculation we don't just do one thing (infect the cells) we do one other thing, we reduce the concentration of the nutrients to starvation levels. We essentially have two variables, the nutrient concentration that cells need to survive and the liquid from the sick individual.

The viral control study protocol is just asking the simple question, what happens if we do a valid experiment with just one variable, "the nutritional concentration". and what they found was cell death that looks just like "viral" particles. This result invalidates the multi variable control that virology is built upon.

proper studies have one variable that is being tested and do so with a mirror experiment without that variable. then when we get a result we can hypothesize that one variable is producing the different results