Natural solutions used to clean wood are most often acidic, with some type of oil base added to help protect the wood. You can use white vinegar for the acidic half of the solution, but what oil you use to help polish the wood is up to you. Olive oil and linseed oil are common agents, along with small amounts of aromatic oils to give wood a pleasant odor.
Treated and Untreated Wood
Most wood found inside homes has been treated in a variety of ways. Many mills require wood to be soaked in stains or preservatives to help it last longer, which changes the chemical composition of the wood and how it reacts to temperatures, pressure and moisture. Wood taken directly from trees is more likely to wear, warp and respond to chemicals than wood that is used indoors.
Likewise, most woods used for furniture or flooring is treated a second time with a sealant or lacquer to protect it from scuffing and wear. This is important because of the effect of liquids on wood, especially wood that hasn't been sealed. Wood used for floors and furniture is dry, dead and no longer growing. It can absorb moisture very easily. Taking in moisture will cause the wood to expand or crack and make it a friendly place for mold or fungi to grow, which is why the wood is sealed. If you are cleaning wood that isn't sealed, then you should only use oils that the wood can absorb without damage, such as linseed oil.
Many wood floors can be prepared for an oil-based cleaning by first washing them with a water and vinegar mixture. This will remove any surface dirt and prepare the wood surface for a deeper cleaning with oils that it can absorb. The vinegar adds a slight amount of acid that acts as a natural abrasive, chemically prying up deposits that may be stuck to the wood. Any type of oil and vinegar mixture should be mixed at a 1:1 ratio.
After a preliminary cleaning, you can use a mixture of white vinegar and oil to wipe the wood. This will both help preserve the wood from further wear and give it a healthy sheen. Most recipes call for half oil and half white vinegar combinations, but you can try and test different quantities if you desire. If you are more concerned with polishing wood rather than cleaning it, olive oil is an excellent natural polish. It will not lift dirt like an acidic formula will, but it does give wood a deep luster after the main cleaning is finished. You can also add a small amount of aromatic oil to your mixture in order to give the polish a pleasant scent.
Tea is also used as a natural method for cleaning sealed wood floors. A black or green tea can be made by boiling water in the usual method, then allowed to sit until it is room temperature. The idea is that the tea forms a light natural acid that will help remove dirt just like vinegar, but will also give wood a pleasant smell and helps protect it at the same time. This only works with teas that are acidic, such as breakfast teas and green tea.
Don't forget the broom and cloth. Frequent dusting with these simple tools is one of the easiest, most natural ways to keep wood clean. The most important part is to make sure the dust is going somewhere--sweeping should always be done with a pan to collect the dust and rags should always be a little wet so they can pick up debris.