I use a shower handle with suction cups to support mine. I do clean all grit/grime off the wall first. A little water on the wall to increase the suction “stick” and bungee the stack to the handle.
Admittedly my rig is older and no body paint so YMMV.
Marvin (and Eileen) - Weekend RVer On A Budget
1997 34’ Gas Bounder / F53 Chassis | Towing 1996 Ford Ranger on Acme Dolly