Why not just shoot it down the bore?
I would be extremely worried about suppressors indexing on the shoulder of that thing as well as tolerance stacking issues all leading to a baffle Strike.
And the bore? Why not shoot CO2 through the front of the can????
I have not seen it in retail but a suppressor website had something about dB. Foam. It’s from Inland Co and is supposed to be a lubricant and protectant for suppressors that also abates oxygen in the suppressor and helps with first round pop as well as drop another couple dB for the first few rounds. For $30 plus shipping a can and not hearing anything more than media reports I just filed it away ... this thread reminded me ...
https://www.inland-mfg.com/Inland-Suppressors/dBFoam.html
I’ve heard positive stuff about this product
Doesn’t leave nasty gunk like wire gel or the oxidation risk that water poses