Begging nuisance

No NGO is willing to train the beggars how to beg without being a nuisance. In our family flat in Dhaka, we have to face daily the door knocks or the pressing of the bell constantly throughout the day.
Now that I have retired and spend most of the day at home, I have to face this bhikari nuisance, responding to these solicitation daily. Sometimes I feel like becoming a consultant and train the beggars on how to ask for alms pleasantly.
Each beggar has his/her own technique, developed through common sense and intuition, without any formal or informal tutorial. There is the bell-pressing type who won't speak out until the door is opened. The other is the vocal type who won't take No for an answer, and continue to linger, until the door is opened and the No is repeated face to face. The impression is perhaps that that there was a greater chance of getting some alms if the door were opened.