When I was the accounts servant in my cong up to about a year ago the C.O. was supposed to hand in receipts for expenses and the cong only gave him that amount. Some elders and congs, including my one, wanted, at times to not bother with exact receipts and that the co ordinator would simply give a receipt to the accounts servant for the amount given to the co, as long as it was the average amount each time. We even got a letter last year telling the elders not to use cong funds to give him a bit extra. This had been happening in some countries. The green handshakes were a new one to me though.