Poster #16,
Really? Didn't you notice that I clearly listed a number of instances ref your wide claims about prepping?
You had made your claims about prepping without posting any details of how you actually prep but now, all of a sudden, you duck & dive into wild fantasies instead of actually responding to my brief list.
In your post #14 from: "Prepare your walls ... to ...practically zero" and "expect success" you claim to have cracked the poor success rate using Mfr's advertising blurb.
There are plenty more examples I can present for you, not least technical conversations with BCO's & RICS surveyors.
None of them thought painting masonry was a good idea. Neither do I.