I am glad Callie is feeling better. I had never had issues with Jada and her anal glands before either. I was shocked at what the vet got out of hers

No wonder she felt bad.
My vet told me that washing her little bottom with a warm wash cloth would help to keep the anal glands from stopping up or at least help her be able to express them herself a little easier. He told me to hold it on her little bottom for a few minutes every day. It has been a couple of months now and she hasn't scooted or been biting at her bottom any at all.
I am like you Taylor, I would never try to express them myself, I would be terrified of hurting her.