Everyone has menial chores in his or her life. Unless you are a member of the ruling class of a country, you can expect dishes to wash, floors to mop, or even junk emails to sort. A great deal of our lives are filled with such time-padding chores and events, and if we think too much about the amount of time that goes into them, we might get a little dispirited. The good news, though, is that this might be one place where multi-tasking can be used for good instead of for ill.
Think of menial task time as writing time.
You've heard before how many writers come up with their best ideas when they're not writing. It's when they're fishing or cleaning or watching bullfights that the best ideas come creeping into their brains. So why not use your menial task time a little more productively? In general, concentrating very hard on scrubbing the kitchen counter and thinking about something else while scrubbing the counter will still achieve a clean counter, so allow yourself to think about your writing projects. Focus on a problem in your story that is currently baffling you; allow the busy work to be a distraction, loosening the snarls of the story problem. Work at it gently.
Gender studies side note: In the past, and still today, women are asked and expected to do a great deal more of these menial-task things than men. It's part of a way our culture (and most human cultures) has of downgrading the importance of women's thoughts and creativity, an expectation that while men are doing the important creative work, women can do the dishes. Be aware of this as you cheerfully take on that extra task. Don't be afraid to value your own serious creative time. Tell a coworker or a spouse or a significant other that you need your non-chore time for work and reflection too.
Another way to use that menial task time as creative time is to practice your language. Think about describing what you see in a fresh and precise way, choosing the words carefully. We all talk to ourselves in a running interior monologue ‚Äî so why not use that monologue as a chance to improve our word choice and observations? Writers are constantly working on our to improve their articulations of things; no matter how boring your surroundings may be while answering the mail or sweeping the floor, there's some way to describe it in a new way.
So how are you going to use that normally empty-headed way? How will you emerge from a day of errands and chores with your sanity intact and your creativity still charged? Remember that you are the writer, and you carry that ability with you wherever you go.