Is there any danger in real life scenarios if I just epoxy up the anti-siphon valve on my outside spigot? I'm sick of the inevitable failures and water blasting down the side of my house and having to buy replacement assemblies for $8 because the $0.03 rubber washer was junk.
It's really just in case I go and drop the hose in my septic tank and then loose water pressure, and then decide to get a cool refreshing glass of contaminated water right?
Pretty much that's the reason. Or if you were using a spray fertilizer, dropped the hose and got a drink of water. You could just install a basic hose bibb without, or (in my area) the anti-siphon are threaded on a hose bibb. It has a breakaway screw. You would need to drill out the piece of screw.
If you epoxy up the spigot there's a possibility of contaminated water back feeding into your water system. Many diseases lurk in contaminated water. This is why it was created. Yrs ago we used to just use those bibs for the garden but then the issues started.