A brilliant idea!
http://www.maannews.net/eng/ViewDetails.aspx?ID=423646

GAZA CITY (Ma’an) -- One Palestinian man was injured on Sunday and two others were reported missing after Egyptian authorities pumped sewage inside a Rafah smuggling tunnel running underneath the border with the Gaza Strip, medics said.

Palestinian medical sources told Ma’an that a tunnel worker was hurt and two others went missing inside the Rafah tunnel as a result of sewage pumped in from the Egyptian side.