It’s hard to imagine any restaurant volunteering to be asked about “lips and eyeballs” in its food products. And yet these are exactly the kinds of questions people are lobbing at McDonald’s in its new YouTube series starring "MythBusters" host Grant Imahara. The campaign is called “Our food. Your questions.”

During the second quarter, according to CNN, McDonald's sales shrank 1.5 percent, and in a recent Consumer Reports burger taste test, it ranked dead last. “McDonald’s knows you have a lot of questions about your food,” says Imahara in the series introduction, before he goes to the Cargill meat-processing plant where McDonald's meat comes from. “And they’ve hired me to find out the answers.”

In what looks like a carefully scripted tour through the Cargill plant, Imahara meets with workers at different levels of processing McDonald’s meat. In response to the question, “Are there lips and eyeballs in there, Jimmy?” Cargill Operations Supervisor Jimmy Rendon answers, “No, it’s 100 percent beef trimmings.” And when asked about the infamous so-called pink slime or “lean, finely textured beef,” one worker says emphatically, “We don’t use that in our burgers.” At least they don’t anymore: McDonald’s says it stopped using “pink slime” or lean beef trimmings treated with ammonia sourced from Beef Products Inc. in 2011, CNN said.

While fast-food franchises such as Chipotle, in which McDonald's was once an investor, boast the use of organic, family-farmed and local ingredients, McDonald’s is still answering questions about whether or not it “pours[s] in wood pulp” into its meat (no) or why its food doesn’t rot (it does). But the PR campaign has to start somewhere.

McDonald's has also used its Twitter account to engage directly with customer questions.