Is it possible to increase the lifespan of a computer processors. I was reading an article on the internet that said that the processors should be cleaned at least once per year.

If you have an old processor that needs a cooling paste then you can apply that paste once a year to make sure that your computer will be cooled while running. Today's CPU's have large heat-sinks on top of them that they don't need cooling pastes. I guess the cleaning part is with the heat-sink because the CPU is protected from dirt.