Scientists found a large hole in a pipe running from a couple's toilet.
"A scary situation, especially sitting at the bottom of a septic tank and you don't know that anybody's coming to get you," said paramedic Nick Wettlaufer.
The advisory warned residents not to swim, fish or boat in the affected area.
The men were sent into the 30-foot tank in New Delhi with no safety equipment.
Globs of fat, food scraps, napkins, condoms, human waste and grease are just some of the ingredients often found in fatbergs.
Philadelphia University designed anti-microbial unisuits to protect athletes from contaminated water.
The study identified households where sewage was being misdirected into waterways.