Talk about a dirty scam. Federal prosecutors in Florida say at least three people working for a septic tank company duped customers into buying about $1 million in unnecessary products — in some cases enough toilet paper to last more than 70 years. More than a dozen customers were told they needed special toilet paper to avoid ruining their septic tanks because the federal government changed regulations on toilet paper. The federal government does not regulate septic tank products. The trio pleaded guilty in federal court to conspiring to commit wire fraud.