Fork damper circuit reconditioning
Short answer, no, there isn't a non-replacement option at this point. 

Partly because the Dash is a very basic shock, and thus repair becomes not cost effective compared to replacement. 

Repair in this case involve replacing the damping cartridge, seals, and oil, which is basically all the internal parts if it's an air sprung model. 

(A coil spring model would also have a spring side.)