I had issues with pain from squatting not because my glutes were too weak but because I was not activating them properly as stabilizers, AKA dead butt syndrome. From that perspective the main importantce of bands, or bridges or whatever is to teach the body to properly use the small stabilizer muscles that can get inadventently inhibited due to injury or underuse, not get them super huge or much stronger so it really shouldn’t take long, weeks to a month I’d say.