I love controversy. There is absolutely NO reason in the world to use boiling water to clean your front stuffer.
Unless of course you want to then that's the only reason you need.
Using boiling water will speed the evaporation of the water, but that's all it does. Boiling water does NOT break down fouling any better than cold water. Soap helps make water "wetter" and for that reason it makes water a little better solvent.
There are so many "home brewed" solvents and they all work well. The trick is to get the barrel clean then DRY , then oil the bore to prevent rust. In other words what ever slovent you're using has to come out. Dry the barrel of solvent, then use an alcohol patch to absorb any remaining moisture, dry again then oil.
Incidently when I was boiling my barrels (I don't anymore) I would dry them well then run Bore Butter, lots of it, down the hot barrel and NEVER , not once, had any corrosion. This is just my personal observation, but I believe Bore Butter does "season" the bore and makes clean up easier.
If the barrel is cleaned well, dried completely, Bore Butter will prevent rust as good as anything else.