Any porous surface exposed to the environment, foot traffic, or machine traffic, will get dirty very quickly. In areas where aesthetics matter, continued efforts to maintain cleanliness can be a tedious. In order to clean the surface properly, removing dirt and debris from the pores or crevices of a floor is vital. To accomplish this task, there are two main options.
The most common method for outdoor surfaces is pressure washing. Generally, the cost, process, and eventual effect of pressure washing provide excellent results. There are many quality, reputable, and professional pressure washing companies in any area of the country.
Due to the tremendous force created by a pressure washer, there are often areas where it is recommended they not be used. For those areas, the second, less common method can be used. This method uses a mix of chemicals to accomplish the same task, often with equal or more favorable results. The reason is because the chemicals penetrate further into the surface to completely lift all of the dirt and debris causing the unsightly mess.
The mix of chemicals used will depend on the surface. Where renting a pressure washer to do it yourself is normally acceptable, leaving the chemical process to a professional is a better option. A professional will be sure to utilize the correct ratios of cleaners and neutralizers to be effective, safe, and without causing damage to the surface.
So your choices are by force or finesse. The wrong choice could cost you.