Interesting thing about window cleaning and JWism. They do seem to run together. Lots of JW's that I know are in the cleaning business. Some work for others, some do it solo, some own a small cleaning company. If I go by what the self employed cleaners tell me, then they make a decent living. This seems to be a very common job for the less educated.
Interestingly enough, in the Hispanic community there's a very common job for the better educated, the type of people who could have gone to ,or actually attended university. The job is translator, often working in the court system. I actually believe that this type of job is even promoted by the "job counselors" in the congregation. It's a job where you don't employ critical thinking skills, even though, you are likely to be very smart.