A smaller badger brush like this should still work well. However, because it is badger it takes longer to get enough soap into the brush when you lather from the soap puck. If it takes 20 seconds to load your synthetic brush it might take twice as long with a small badger brush.yeah it is 19mm and to be honest I had no idea about knot sizes would make differences, I just went with the idea that badger would always be superior no matter what size, i was wrong.
And about the pictures, I actually uploaded 3 pictures one was when brush is dry, but for some reason it did not appear on the post, I am putting it here again. View attachment 1835057View attachment 1835060