What you'd need is something that:
- only attaches to the seatstay (top of the swing arm)
- attaches to a rear dropout screw eye, mounting point (not sure what it's called) if there is one and the seatstay
And, won't hit the seat when the swing arm moves.
Thule Tour rack (not a recommendation - I've never seen or used this device) is advertised as something that will work for full suspension bikes and only attaches to the seatstay Load capacity 25 pounds on the rear.
Other racks attach to the rear axle and the top of the swing arm - some are held on by the quick release. Skewers seem too fragile in my mind.
I wonder how the ride would change with 25 extra pounds attached to the swingarm.