not what you think is wrong with him.
Based on what you might tell me and based on what I already know there might not be a problem and might not be a need for assist feeding.

A lot of vets when told that a snake is not eating will tell you to assist or force feed, in the MAJORITY of cases it is ABSOLUTELY not necessary.

If you are not experienced and it is necessary to assist your VET should be able to do it himself.

The reason I am asking questions is to help and establish whether or not the animal even need to be force fed and put through additional stress.

YOUR husbandry could be the issue here (it was already the issue that caused scale rot), if you solve husbandry issue if there are any left you will help your BP resume feeding on it’s own.

Again helping with precise answers (size etc) will also help us determine if force feeding is even necessary.

Force feeding if not necessary could do more harm than good in your case.

But hey what do I know I am not a vet.