How do they keep the outdoor models so clean at the various Legoland parks?

Question

I've visited Legoland in California a few times and was always impressed with the lack of accumulated grime or bird "strikes" on the outdoor displays. How do the park employees accomplish this feat? What combination of tools and/or techniques do the Parks utilize to keep the models free from build up?

Answer 1

I've been to Legoland Windsor (in the UK) on one of the days they were cleaning some of the boats, and it looked hard - all manual work, with a large toothbrush and plenty of elbow grease