Interdental brush for swollen gums~

I discovered this product last year when I went to the dentist because my gums seemed a bit swollen and I needed a scaling. The doctor told me to use this properly along with dental floss. I thought I was brushing my teeth diligently, but there's still a little bit of something left behind. I've used dental floss before, but this is my first time using this product. It feels refreshing and nice if you use it gently. You definitely have to use it gently. I am genuinely envious of people with healthy teeth.