Whitewash is one of those old-fashioned products we here about but never get to use. The only time we get to see it is when we scrape off flaking paint that was painted over whitewash without proper sealing. Up till the 1930's whitewash (calcimine, often called distemper for inside work) was the main paint used on masonry and plaster. Thankfully it went out of favor.
Of course, with the return of "earthy" building designs whitewash is making a comeback. Special Limewash paints are now sold at a higher price than the best acrylic paint, and on brickwork the coverage is minute. Mind you, we don't have to finance the life-style of some marketing-mogul; whitewash is as easy as a wink to make and costs next to nothing. Take one bucket of rock lime (sometimes called fro lime) and add a couple of handfuls of Casein glue (skim milk powder), mix in a drum, add water, and watch it boil - don't touch it. Let it stand for a few days and then add oxide color for a tint, and there it is.
Now whitewash is one of those products which has been used for eons - from the Egyptian pyramids to Roman frescoes. And believe it or not, in the Bible it's a kind of swear word. Paul the apostle called Ananias the High Priest a "whitewashed wall". Jesus called the religious authorities of his day, "whitewashed tombs." These may not seem strong character slurs, but they are indeed very strong - them there are frighten words!
Chapter 13 of the book of Ezra contains most of the Bible references to whitewash. They refer to whitewashed walls. These are walls roughly built and then covered over with a thick coat of whitewash to hide the lousy work. Yes indeed, we all know about shoddy workmanship hidden by a thick coat of paint. Ezra's point is that the people of God in his day had built their lives out of rubble and then plastered it over with religious whitewash. They were hypocrites, godly do-gooders on the outside, but rotten on the inside. Just as a rubble wall will easily fall over, even though it may look good, so will the life of a hypocrite.
"Whitewashed walls", clean and bright on the outside, but weak and flawed on the inside. And aren't we all? So then, how can we stand before The One who sees through the whitewash? Well of course we can't, unless we put on the "white robe" that Jesus provides.