Rocket mass stove

Is it possible to design a system/retrofit a rocket system to an existing masonry chimney that has a horizontal flue opening? I currently have a wood stove with the exhaust port that has the stove pipe coming out of the rear of the stove and entering directly into the masonry chimney thru the the wall. The chimney is 28 foot and if memory serves me has a 8x12 flue liner. I'm concerned that there might be problems with drafting as the chimney can become cold soaked, after being gone for days I must light a paper fire in the exterior clean out to warm the chimney prior to starting the wood stove. Any insight and or thoughts would be appreciated. Thank you, Jack ps my old wood stove has 6inch pipe that runs horizontally into my masonry exterior chimney.

It is possible indeed. And there are commercially available "insulated chimney liners" that are made to drop right into existing masonry chimneys.