Thanks- you hadn't mentioned his ventral red areas, or puffiness of the scabbed area. That's why it's important to see a vet, & in person whenever possible.
If you can inject antibiotics, you should be fine to tube-feed. I'd rather tube-feed a snake any day.Do talk to your vet- I have a feeling that she's had people do it wrong in the past & totally mess up, & she doesn't know where you're getting your information from. There's plenty of misinformation around.