i would not dip!
Unless you fancy a larger bore barrel!
I sort of claim a little chemistry knowledge - the anodizing is a coloured increase in the aluminium oxide layer on the barrel and if you dip and fill with NaOH it i expect you to remove the honed oxide from inside the and some of the surface
- knackering the barrel!
I have not tried the dip process, but I wouldnt try to do it that way.... spray, leave and wipe with Mr Musule would be better.
Cheers
A
Look up anodis(Z)ing on on Wikipedia for more info