I would not rod an airgun barrel. It is not necessary.
Was the brush bristle or wire. Both are not good news IMHO.
Get a pull thru and some .22 patches......some good quality gun oil and pull through till they come out clear. Then a few dry ones.
A clean barrel can actually open a group until it leads up..... or it can tighten it. Each barrel os different.
The pellets are buggered.
In a battle of wits I refuse to engage with an unarmed person.
To one shot one kill, you need to seek the S. Kill only comes from Skill