In the UK we call them "window cleaners" and a lot (and I mean A LOT) of JWs do it. I remember going to one Kingdom Hall to give a public talk and virtually every car or van in the car park either had a ladder on it or had a ladder rack. There are a few reasons for this particular employment - family businesses , no qualifications required , no need to work with "worldly" people , flexible hours so that you can get a morning off for the ministry etc.
There always seems to be two kinds of JW window cleaner with very little overlap...
Type A is a grafter - often he has a few brothers (or occasionally sisters) working for him as his business has developed (usually type B who are too lazy to develop their own business). He gets up at 6 in the morning to do his business customers and will still be at it well into the early evening. You see him walking or driving briskly between calls and he makes good money - nice car , holidays abroad a couple of times a year , bought his own house. Not usually a pioneer - too busy making a good living and servicing his clients. A lot of these brothers have invested in their business and have special equipment such as deionised water spray systems etc.
Type B is often still in bed or hanging around the house till 11 , especially during those cold winter mornings and works (I'm using the term lightly) till about 4 o'clock , allowing for a leisurely lunch break and a few cups of coffee & the odd bacon roll from friendly customers. Works maybe a couple of days a week or so - never when it rains or "maybe looks a bit like it is going to rain." Sometimes a pioneer , sometimes not. Usually plays the system by claiming to work a total of 16 hours a week so that he can get lots of state benefits - rent paid , family credit , even free school meals for the kids. (When questioned by the authorities he claims that he has a bit of a bad back or a dodgy ankle as a result of falling off his ladder , so is unable to work any more hours). Always happy to lean against his ladder & talk all day with passerbys. A bit unreliable so sometimes loses his customers , though most are quite loyal as he is "a nice bloke".