In our modern day way of looking at disease all bacteria are considered bad. We have more bacteria in our body than cells and if we didn't we'd die, as they do a whole list of things including digest food, ward off bad bacteria etc.
Soap does not kill everything and that's a good thing, because we would die if all the bacteria were killed in us. Bacteria has been found in deep ocean areas above volcanoes where the heat, steam, acidity was previously thought to kill everything.
Soap kills bacteria within a certain spectrum leaving everything else alone. Same with heat/antibiotics, you name it.
Another thing about soap is that it can be a gift that keeps on giving if the residues linger and the bees pick it up and ingest it. It may kill off the beneficial bacteria in their gut causing them to starve to death. I read of someone who gave his bees a very tiny amount of colloidal silver to help them rid themselves of a pest. The bees slowly starved to death, yet lots of humans consume it daily for health reasons.
I personally only use soap when my hands are really dirty and I have a social occassion or they are greasy. Your skin absorbs everything it touches in varying degrees and I don't wish to absorb soap, which to me is really an antibiotic, so I don't go along with this advertising and hysteria created by the soap companies.
I cannot tell you what to do, but I would be mindful of what you are putting in the hives as you might end up with no bees or contaminated honey.
BTW charred wood is carcinogenic from what I am led to understand.