I'll usually give the missus a few bob to donate to the local temple when she goes to tambon(make merit). I think that's safer, less chance of getting caught up in something dodgy where only a small percentage of the cash actually gets put in the beggar's pocket.
I once knew of an official person who'd dress in rags on his days off and go around begging in Sukhumwit Rd. Wanna avoid shit like that.
