I don't know what you mean by 'treated with them'. As I understand it the only substance which would have come into contact with any part of the apartment would have been distilled water used to moisten a swab. The swab would then be tested with the substances, not the source stain.
https://www.youtube.com/watch?v=2aPz_AV0t3U
As well as the dragon's blood used in the search for usable fingerprints ... chemicals for the detection of blood were also used
SnipAlso, innumerable tracks [footprints] that were taken to be canine in origin mixed with red- and white-coloured chemical products, as used to see fingerprints
SnipThere proceeded the search for possible blood traces in all of the apartment, using a variable- wave light source appropriate for the task.This search resulted in the detection of several spots having a red-brown tone that suggested blood,
which were subjected to a "Kastle-Mayer" peroxidise test, the result obtained, in all cases, being negative.
There also proceeded the observation and search for blood traces inside the apartment
using a chemical product to find latent blood traces. In the application of the referred product no results characteristic of the presence of blood traces were found
http://www.mccannpjfiles.co.uk/PJ/5A_FORENSIC_4_5_7.htmWe've all watched the video of a dog familiar with crime scenes reacting excitedly on the approach to apartment 5A .
Why would he do that unless, to paraphrase Martin Grime, he smelled a scent with which he was familiar? Could that scent to which he was familiar have been the scent of a crime scene where he would be able to participate in what to him was the game of search? as per his training.