Nu uh. The acid is applied at, say midnight and not discovered until the etching process is well under way. You can hose the acid off, sure, but the glass is already destroyed and has to be replaced.
AFAIK the products work fine. The application is the major problem. The product we were instructed to use on some projects we’re working on is extremely intolerant of mistakes and even the slightest mistake will…allow water infltration, react with the bricks in unexpected ways, not cover gaps in mortar properly, causing efflorescence which will eventually cause the coating to break off and chip off.
Now that I think about it, our guy recommended an alternate product that supposedly installs fine, but provided poorer performance (i.e. instead of an impervious coating, it was basically several “sacrifical” layers, each time you removed it, you took off one layer, as you ran down the number of layers still on the building, you ran into some potential problems: i.e. the coating reflects light differently, making your building look two-toned (think before/after photos, but this time on the same wall) and you run the risk of wearing the product down to the wall and not realizing it, then you’ve got part of the grafitti on the wall and part on the coating, which you’ll have to sandblast/paint anyway. Granted, that will only happen if your maintenance crew is particularly imperceptive. As I understand, one has to remove the coating in its entirety before replacing sacrificed sections to avoid the problems mentioned above.
In my experience, the removal is as bad as putting the stuff on: both will kill any landscaping that it comes in contact with and if it gets on your windows or the aluminum, it can cause pitting.
The Hydrawash appears to be checmicals to remove paint once applied and not an anti-grafitti coating proper and the other one is a sacrifical system.
If applied properly (read the installation manual carefully, they basically exclude themselves from a warranty as something will void their conditions), I think it is an excellent system. It’s also a maintenance headache though: if you replace masonry, want to paint, etc. you’ll need to remove it and have it reapplied.
Sooner or later some idiot kid is going to figure out how to cause it to fall apart and cost you even more money having it reapplied though (no, I won’t tell you how to do it).
If you do decide to use one of these products, research the various products yourself (you may be able to call an architect and have them recommend something, but you gotta find them first), read their installation guide to see if they disqualify your particular environment, call them to find certified applicators list (if they don’t have one, I’d be leery), then talk to the contractors. Make sure that you get a bid and then ask if they will warranty the installation even if the manufacturer’s warranty is voided because of their shortcomings (of course, enforcing that will be a pain in the ass as some problems might not pop up for months as water slowly infltrates), then see if they resubmit a bid that’s higher to make up for the warranty.
The only reason I go this far is that not being familiar with the process is costing us about…well, it’s embarrassing.
thanks for all your help Chainsaw, we’ll see how some of these products works on the ‘War on Graffiti’ (imo should be the worlds next war 
)
Years ago we built a bank in West New York, New Jersey. Across from the bank site was a supermarket, and a middle-aged man was painting the exterior, covering up tags. Meanwhile, kids were tagging the wall he’d painted the day before. We speculated that this fellow had been at the task since Kennedy occupied the oval office.
I like the solution offered by Bosda. 