A new one for me. After reading about it, I don't think it's going to do the same thing as grit. Grit is basically tiny bits of stone that help grind up seeds that pigeons eat. Most other birds shell their seeds and don't need to grit. This bird charcoal is also ground up, so I don't think the doves would eat it, but I could be wrong. I don't guess it will hurt them.......just don't think it will take the place of grit.
Charcoal is very beneficial to birds. Helps purify the blood and keep the oxygen in it, I believe (I can't remember, but I did read something about it somewhere before ). BUT it's not the only thing they need. Plus the kind you have is probably too fine for pigeons to want to eat. A good grit mix is made of crushed oyster shell (for calcium), granite (for grinding), and charcoal. All of that is in my red grit, but you won't find that at pet stores. Places like Tractor Supply and other farm/feed stores should carry chicken grit, which normally has oyster shell and/or granite.
One thing about charcoal I do remember though, is that it should be given in small amounts. And that it also needs to be taken away when giving supplements or medicine, since it can interfere with the absorbtion of some vitamins and medicine.
Charcoal is good for the pigeons, but you just mix a very small amount in with their grit. It aids the digestion and is said to neutralize acids in the stomach. If you don't have grit, give them some course sand or gravel til you can get some. It'll be fine. It's what I use when they are on an antibiotic that they are not supposed to have calcium with. Their grit contains calcium, so they can't have that while receiving those meds. In the wild, they pick up course gravel and small stones, so it'll work.
She has RN doves folks. go back to the pet store when they get the grit in and get some of that, it is fine for doves. I give mine the kaytee hi-cal grit, it is granite, oystershell and charcoal bits as well.