I must be weird . With a cpl exceptions * , I usually break in holsters Bareback and Dry . Make funny face , shove hard , snap in place , and set aside to check in a week or so .
Exception - If you need to make major adjustments , or are seeking the band boned look so close that you can read the s/n , then wet the leather , and use gun condom .
That's how I've handled break in for most of mine, unless the fit was way too tight. My last few have been throw the gun in and let it sit for a day or three. I've only done the bag method for one Galco holster.