Most professional holster makers today recommend wrapping the gun in a plastic bag and inserting it in the holster.
Let stand over night then check.
If it's still too tight add another bag and give it another night.
Letting it stand for a week is not necessary and may stretch it too much.
Wetting a holster to mold is how it's done.......... to a NEW, unfinished holster.
Once a holster is finished, it's not intended to be re-wetted and re-molded because it usually has some oil applied and a surface finish added which will make re-molding it difficult.
Holster leather cannot shrink, it can only stretch, which means that when you re-mold it you're stretching the leather, and there's a risk of it stretching too much in the wrong areas.
Leaving a gun in the holster until it's dry or nearly dry runs a high risk of it stretching too much.
Again, since holster leather can only stretch, there's no way to shrink it if it comes out too loose, and you'll have ruined it.
Most all modern holster makes recommend using NO oils or leather dressings on a modern defense type holster.
They almost all recommend using a neutral shoe polish wax or Johnson's Paste Wax.
The answer to smoothing up the inside of a holster is....use the holster, it'll smooth up as it's used.
If you just must do something, "Leather Lightning" from Mitch Rosen is about the only thing most makers will recommend, and not all of them.
https://mitchrosen.com/products/additional-products/