Clay shooters have been doing it for years.
Helps with the pattern and reduced shot deformation, and actually reduces felt recoil a little.
Is it worth it?, depends on what you are going to use the shotgun for.
If its a chrome lined barrel, then most smiths won't touch it to begin with.
Give Casey and Tactical Ordinance a call and run it by him. He does the Vang Comp upgrades to shotguns with great results