Take a picture of the inside switch and send it to Outlaw service so they can verify which version. I would hesitate to spray anything without Outlaw weighing in first.
I would take this approach. There's a possibility that they mean both volume knobs are analog, one sealed, one not sealed in which case contact cleaner would work fine on the non-sealed version. There's also a possibility that one is analog and one is a digital encoder. Spraying contact cleaner in a digital encoder might destroy it.
Please don't use WD40 on electronic circuits. It's a lubricant and will leave a residue behind. Any electronic store will carry contact cleaner. Or you can get it from that big mail delivery place that starts with an "A"
Aperion Verus Grand Towers & Bookshelves, Verus Forte Center, Infinity Surrounds, Ultra-X12
Oppo BDP-203, XBOX360, Xbox One
LG 65" OLED
RR2150 w/Klipsch SCR-2