Unfortunately, I doubt it will work, because it suffers from very similar information problems as direct charity does. It requires donors to have good information about what a prototypical worthy recipient looks like (but having this information seems like a large part of the problem we are trying to solve), or else be able to hire someone who has better information about that than the donor (but Robin provides some strong reasons to doubt that is possible in his more recent paper He Who Pays The Piper Must Know The Tune).
I can imagine (but am unconvinced) that donors can describe the appropriate criteria for worthiness, and that the main information problem is distinguishing honest claims of meeting those criteria from dishonest claims. But the charity angels scheme rewards people for failing to distinguish honest claims, which makes me doubt that the giving that this scheme would encourage has much to do with truly worthy causes.
The “Tell Off A Jerk” variant on this theme seems closer to a workable idea, but it risks producing flame wars where people polarize into groups each of which uses charitable donations to encourage retaliation for the other group’s rude attempts at deterring jerkdom.