I think it works, toxins can transmit into the body not just through the ingestion route but also skin absorption among many other routes. So if there's toxins

I think it works, toxins can transmit into the body not just through the ingestion route but also skin absorption among many other routes. So if there's toxins in the sand of the kind the skin is vulnerable to then that sandbox would be poisonous to the occupants. https://www.cdc.gov/niosh/topics/skin/default.html#:~:text=Dermal%20absorption%20happens%20when%20a,include%20pesticides%20and%20organic%20solvents https://www.cdc.gov/niosh/topics/skin/default.html#:~:text=D....