There are numerous problems with the special paint hypothesis, many of which have been litigated before.
Examples of such:
https://www.codohforum.com/viewtopic.php?p=10819#p10819
Begin there and scroll down. I'll add some additional thoughts here. Invoking a physical barrier to inhibit the interfacing of HcN with the underlying masonry renders much if not all of the heavy lifting done by Markiewicz, Green, and in turn Van Pelt and others as redundant. They argue the interface was unimpeded.
The only expert to my knowledge who invokes paint is Dr Bailer. He argues its presence is the reason for the blue stains at the delousing chambers ~40 years later. This means Dr Bailer is arguing for a paint that is visible today and has not disappeared. There are 11 refutations that Rudolf makes to this argument section 8.4.1 of TCoA, and not one of the 11 invokes the lifespan of the paint (!).
Eyewitness accounts describe the phsyical appearance as that consistent with the revisionist position:
“The gas chamber at Crematorium II [III] was underground. It had gray walls
and a gray ceiling. The floor was concrete....
..... The walls were made of concrete[sic]"
- Shaul Chazan as per Giden Greif, pg 270/271
Was the floor tiled?
No, the floor was concrete
- Josef Sackar as per Giden Greif, pg 99
The floor was made of concrete. There
were windows under the roof and the room was lit by several lamps. The walls
were white, but outside there were red bricks.
Shlomo Dragon as per Giden Greif, pg 153
What color were the walls of the gas chamber?
Somewhere between gray and white.
What was the floor of the gas chamber made of?
The whole floor was concrete.
Leon Cohen as per Giden Greif, pg 297
All of these descriptions are consistent with the revisionist position, that is an unpainted concrete roof / floor and cement-rich plastered interior walls:
For completeness, there was a separate but i guess somewhat related discussion of whitewash / sealant being applied to the walls between gassings, see here for refutation of this hypothesis:
https://www.codohforum.com/viewtopic.php?p=13013#p13013
To conclude, the special paint hypothesis demands very little attention from revisionists.
- Its existence has yet to be demonstrated
- Orthodox experts' arguments (except one, see below) assume HcN / masonry interface was uninhibited
- Where Bailer does invoke paint, he argues it's presence is visible today (1995) and so is incompatible with the BA hypothesis that it has vanished
- This hypothesis reeks of deus-ex-machina and always will unless it is substantiated in some way