Even renting a pressure washer is fairly cheap but the job would take quite a bit of time for one person and anyone who volunteers to pressure wash has to be very careful because they can do damage to the building if they get carried away with the pressure. They can also do serious damage to themselves. Nobody wants to be liable for damages created while volunteering. I do have a pressure washer (and buckets). If you guys figure something out I will be happy to help out. Adjusting the sprinklers regularly is a must. The rust remover previously mentioned is truly magical from my experience. Not sure what it is made out of but the pressure washer or brushes are unlikely to remove the rust stain. I am not aware of the expense to set up but a rust remover can be run directly through the sprinklers too. This does require minimal maitenance.