I don't use squirt bottles…well occasionally I do. The only instance I use it is when the dog is ignoring "leave it". The reason I use SB then is because it is a consequence for ignoring a request, and I can use it remotely. If I get up, the undesired behavior is long over by the time I get to the naughty dog. One of the main reasons I don't use a squirt bottle is that my dogs quickly learned they could engage in the unwanted behavior when the squirt bottle wasn't in my hand. And, yeah...with leave it, I could probably train a more reliable response to the behavior with positive techniques...but sometimes I AM a lazy trainer, especially now with twins
But I always give a cue first, and then use the sb as a consequence...not just randomly squirting to get them to stop whatever they are doing. And I would never use it with certain behaviors like overzealous play, aggression, guarding...because IMO it would raise the level of arousal rather than calm the dog and, as you mentioned, create a "mask" over the real behavior.