.. never seems to go away. And the reason is there's no clear-cut answer.
With some Boa hide boxes are essential, others seem to never use them. Why is this? We do not know.. because there are too many variables involved. Here's a short list:
What type of boa is it, and how old and what size?
Describe the cage..... what substrate?
How do temperatures, location of the enclosure and many other things differ from the set up of others?
When do you attempt to handle your boa?
Do you have other pets, friends, new cleaning solutions and/or after shave on at that time?
Is the boa in shed or had a large meal recently?
Will hide-boxes tame a boa or not ?.. we don't even know what you call a tame boa or how you approach and handle the snake...
No one can give you the correct answer because all these make a difference, neither is it known how these factors may or may not interact with one-another. So while we all like to prognosticate on these subjects (and you have gotten some good replies) all we can really do is pass on our experiences (or what someone else has said).. and those are just a starting point.
It is like the perpetual question.. 'how much do I feed my boa'?.. How the heck do we know?! We don't know how big you want the animal to be, what condition it is in now, what the lineage of the animal is and also most of the variables mentioned above are also a mystery to us.. these all help determine feeding...
So just like the feeding question, all that you get when you ask the question about hide boxes is what has worked for us or not worked for us before. (Sometimes we may make it sound like a final answer!).. YOU have to decide how much to feed your boa and whether or not to provide a shelter, if you should or should not breed him or her, how soon you should hold the boa after feeding.. ad infinitum..
Because of all the unanswered questions about the animal and how it is kept the (sometimes excellent) advice you get here can only form the start of your total husbandry program.. The routine you come up with after watching your animals in your set-ups over a period of time is going to be the best choice.
That's my prognostication!
Gus