Frore makes thin flat electrostatic coolers that would be perfect for laptop SSDs, but I don't know if they're available for purchase by consumers.
The main problem would be powering them. They could potentially draw power from the M.2 connector through an adapter, or soldering to an USB connector, I guess.
The main problem would be powering them. They could potentially draw power from the M.2 connector through an adapter, or soldering to an USB connector, I guess.