I used to organize TEMP campaigns in countries where the "need is great".
This (not very common and not well known arrangement) works like this:
Temporary because they will send you to territories where they have 0 Witnesses and don't know how you will received (cannon fodder). It's like throwing mud at the wall, they expand with several hundred people (always in groups of 2 or more) and then see who has the most success.
Usually 3-4 months (some countries do a 2 month, but it is seldom). 3 months is standard. Another reason is exactly what you have said: money. This is cost intensive. TEMPs get the same amount of money/support as Special Pioneers - monthly allowance, rent support, some help for transportation. No medical / health care. For pioneers from western countries the money is a pity and brings you down to "slave labour" status (in comparison to the wages you would get in your home country). For locals this is like winning the lottery. In some countries that i've been (in Bethel), locals would literally kill to "get the job". Sometimes they would appoint people that where pretty shaddy and strange, but because the territories are far away and sometimes dangerous/isolated, Bethel would accept whoever has legs and wouldn't kill his partner in an attack of schizophrenic attack (although, Bethel had to pull out some people that where behaving more than strange, or fucking the locals - literally like in fornication
After the 3 months are over, they pull everybody out and then it is a numbers game. The places that got almost a new congregation started, get a permanent Special Pioneer couple, the others are dropped. It is a "push-and-pull" game.
This is it in a nutshell. If I remember something else, I'll write.
Oh, I remember one funny episode (disgusting). Two TEMPs sisters had an assignment together in a isolated rural area. After they came back, one of the sisters wanted to talk to me (I was the overseer of the programme). She told me that her partner had a problem. I had heard so much shit from people that almost nothing could "get to me" anymore. She said that during her stay there, they had an invasion of bats (yes the animal) in the house....(at this moment I go: "hhhhhmmmmm, THIS WILL be crazy shit....) "Go on, sister holymary" Then she told me that she found out that her partner would wash the disposable menstrual pads and dry to re-use again, but that she didn't have time and stored them somewhere in the house, also under her bed and that attracted lots of bats.....)
I wanted to .
I couldn't find a good scripture to read.
I let her go and had a couple of drinks to forget the conversation.
This was one of many strange conversations that I had during my time at Service department.