Notice none of these deals with the need to wash one’s hands after touching a dead animal or the article touched by the dead animal. It does mention putting the item in water, but it is still unclean until evening. The magic hour.
Pretty ironic that their soldiers were specifically told to have a tool for burying fece. I guess you can say it is pure coincidence that modern US soliders specifically have a tool for burying feces in the field (Field Sanitaion FM 4-25-10).
Did the Isrealites do it to keep holy? Sure. Did they do it for sanitary purposes? Maybe, maybe not. Did this Field Sanitation technique keep their conditions more sanitary than any other army? Absolutely. They were 4,000 ahead of their time in terms of field sanitation.
Call it evidence, or coincidence.
"Damn. I could build a nuclear bomb, given the fissionable material, but I can't tame my computer." (1VB)Jerome - French Rocket Scientist