ive been doing jet washing for a few years.
When the work comes in the money is really good!
But its not enough to live on really.
We used to advertise on yell.com, but we didnt get a lot of work from there.
Graffitti removal is good money. You need the right chemicals mind.
It is deffinatly a spring/summer thing also, i do get a few in the autumn, but maybe once or twice a year tops.
I enjoy jet washing personally. More job satisfaction as it takes longer to get dirty than windows!