Hills dog food has been used as a substitute for carnivore care for tube feeding....but tube feeding at all is a last or second to last resort for situations like lizardlick's adopted significantly underweight bp that was losing a dangerous amount of additional weight while being treated for the underlying issue for the refusal to eat (RI). It's only meant to keep them going and strong enough to eat once the reason for the anorexia is resolved. The analysis of "can't eat" is very concerning to me. From your picture of him, your snake doesn't look sufficiently underweight to have to tube feed SE. Also a hydrated bp at appropriate temps shouldn't have an issue with ingesting a bit of coco fiber.. Are you sure you shouldn't get a new vet SE???
I'm sorry for derailing, I'm just concerned...