All you have to do is have Raul as a companion when you start the Dead Money add on at the Abandoned BoS Bunker and it will say "you've lost Raul's Regular Maintanence Perk" and that "Raul has returned to his shack" but if you completed the "Old School Goul" unmarked quest and unlocked Raul's Full Maintanence perk it will remain on your list of perks and your weapons and armor will continue to decay 75% slower. This also means you can choose a different humanoid companion and get their perk along with Full Maintanence and either Rex or ED-E's perks. A total of 3 companion perks.
I usually dont like to use glitches but after all the [censored] I had to deal with because of this perk before the patch I feel it's one way Obsidian can make up for it. We deserve a few glitches like this.