Yesterday I was perusing a national news website whose headlines more and more seem to resemble those of a sensational supermarket tabloid. Being a syndicated newspaper columnist, I find this transition most interesting. One particular headline blared about the five things you should NEVER put down your kitchen drain. I’ve been a master plumber since age 29 and have had the very good fortune to replace old kitchen drain lines and unclog newer ones choked with gunk and who knows what. I thought I might discover something I didn’t know. While there were one or two good tips in the article, a few of them had me scratching my head wondering if the author had ever cleaned out a residential drain line to a kitchen or bathroom sink. I decided to share with you my experiences with residential drain lines and let you apply your own common sense. Beware, as a few of the details I’m about to relate might make you squirm just a bit. It’s useful to understand what the inside of drain pipes look like when new and what they look like after decades of use. New cast iron, copper, galvanized iron and plastic drain lines are quite smooth on the inside of the pipe. You want smooth-bore pipe so not...