It is probably true that not all LPs can be saved.
However, in my relatively limited experience I have found that the easier it is to peel off the glue, the less effective the treatment was. Once you think about it, it really makes sense. If the glue has really penetrated the grooves, it will take some effort to take it out.
My theory (can't say I have proof - just indications) is that the glue needs to be thinned a bit, to the extent it flows like honey, poured and set using a paintbrush in a relatively thick layer of at least 2mm on an LP that has previously been cleaned by water or - prefferably - alcohol. If there is still some alcohol on the surface, all the better.
I have tried this on an LP that had unbearable crackling noise as well as increased distortion. It hasn't become perfect but is perfectly listenable now. I will be trying the same process on some of the worst LPs I have, most likely classical music - as they are unbearable with constant clicking. This time I will make sure to make a before recording.
PS. I understand that "flowing like honey" is far from deterministic. Will try to find a better analogy.