good idea with the HQ concentrate. Much easier to handle - something like a concentrated KBr or BTA to dribble in to control fog? Yes, I know, not the same thing, but same idea.
Locally I can't locate propylene glycol but the ethylene glycol is everywhere.
As for the sulfite, which is known to 'regenerate' HQ, and does nothing for glycin - so why add it? 'Save the Planet' 50 years on?