Don't apologize, we're all beginners at this at some point, and we all encounter new situations and need the advice of others. I think next time you unwrap your duck's foot you should post pictures. There isn't always a kernel of infection that pops out. Keep your duck out of the water and the foot bandaged for a couple of days. By then it should be scabbed over, so you can give her a good swim and take another look at it. When I have had to cut into my duck's foot, or pull a scab, I've usually filled the hole with antibiotic ointment - just not the kind that has pain reliever, then bandaged. Sounds like you did a good job. It's hard when it's a bad one, but you can do this! They can recover from bad bumblefoot. You might try antibiotics. I know you can order them for fish online, and hopefully someone can recommend something or you can search some threads here that talk about which ones are best.