They are reporting adverse effects.
It's bound to that specific book. Not any copy, that specific copy of the book. However, It
is significant that it is the abermelin.
My point is not to cause trouble for oneself and others in the process of "getting rid of it".
First, here is some support for my assertion regarding buring paper and parchment in this context.
"Initiates begin a "formal commitment" that is signed in blood and burned in order to participate fully in Satan's work upon humanity, to imply a growth in spiritual knowledge and personal power." - Wikipedia:
If the intention is to "get rid of it", burning the parchment with the writing is not getting rid of it. It makes it
more difficult to get rid of it. At the very least, I think it's useful to be aware of the distinction between burying and burning.
Second, the underlying mechanism of this sort of object, specifically a book of the abermelin, is a sort of pyramid scheme. If the object is not rendered inert, and it is "gotten rid of" in a manner which passes it on to another, then the individual who is "getting rid of it" is included in that pyramid scheme. They will be benefitting from causing harm to another. They will likely be temporarily rewarded for this, by the demon(s) which is/are bound to the object, but the participant will ultimately pay for this with the compounding interest inherent in the pyramid scheme.
At the top of the pyramid is the one who intially bound the demon(s) to the object. They are making a deal with it/them. The demon(s) will repay them for the priviledge of punishing others who are consenting to the their punishment. Then any and all who pass on the object are participating and increasing the reward ( or the debt the demon and its horde owes ) to the one at the top. Along the way, those who pass it on will themself be rewarded, encouraging the free sharing, gifting, of future similarly crafted objects. It's very sneaky because part of the reward is ending the punishments. So, the individual thinks they did the right thing "getting rid of it", but, they're still participating whether they know it or not. And so, individuals might become careless with how they "get rid of it" through word-of-mouth. "Oh, I just got rid of it, and everything got so much better for me."
When an individual obtains a book of abermelin and possesses it more often than not, there is implied consent to participate in the pyramid scheme. It doesn't need to be fully "informed" consent, it still grants permission for the demon(s) to reward and/or punish the participant. That's why mundane books cannot be setup for this sort of craft. There is no consent implied for possessing a chemistry book, for example.
If the book is burned, it's complicated discerning precisely what happens next. The demon(s) may retaliate, I don't know. Also, if the demon(s) are freed from their bondage, any harm they produce is linked up with the one who burned the book. And even if burning the book works to eliminate the chain of effect from the pyramid scheme, it's a lot of work to burn a book completely. However, I
do know what happens if the book is buried, and it's rather quick and easy to do it.