I'm not saying the sand caused it, I'm saying that the lady's wire brooder floor most likely caused it and the sand just caused it to get worse. I'm not judging you chicken-keeping, everybody makes mistakes :D
I agree. I think the sand might of caused the bumblefoot on PaintedFeather's chick to get worse, so you should probably put some bedding down for her, PaintedFeathers.
I said to hold her for a couple of minutes (don't put her feet on anything) so her feet can air out. Then I think it would be okay to wrap, just check on her every few hours
Just smear on a thin layer, you don't need much at all. I wouldn't wrap her foot or anything, just hold her so her feet don't touch anything and let them air out for a little bit.