Years ago I scored a pair of clarki this way, bought a Sebae/Crispa from petco, a clarki swam inside the mouth.
The petco employee said "oh he just ate that fish, guess you got a freshly fed nem"
I said I'll take the other clarki in that tank too, and I rushed home fast as I could, hoping the clarki may come out of the nem.
It did, but it was really jacked up like it was being digested, but it eventually healed and recovered.
The two clarki's paired up, had them for years and had the crispa for 5.5 years