My neighbor is not a plumber, but he added some pipes I needed to divert water to my kitchen sink. I didn't want him to do it, he insisted on helping and I didn't want to upset him. He poked his fingers into the pipes, coughed on them, and used his spit to adjust the teflon tape. He's over 70, wheezes through his mouth, is foul smelling and chronically ill. Is there a way to sanitize the inside of these pipes? I'm tempted to dismantle them all and wash them with toilet cleansing gel, like Domestos. Should I worry?