Lately, I've started to really crack down on taking care of Sasha's teeth. I'll admit that I've been pretty lazy these past few months

but I know caring for her teeth is really important.
I'm trying to brush her teeth at least every other day. I had forgotten that I had a bottle of Petzlife Oral Care Gel so I'm going to begin using it again.
My question is, can I apply some to a toothbrush and brush her teeth with it or is it better to just simply apply the gel to her teeth/gums with my finger?