Hey gabacho! You want to buy some shicken?
What was called a lingua-palatal fricative is more likely a voiced palatal fricative and the source of schiken where the hiss ends with the back of the tongue being drawn up against the hard palate all in one breath.
The "S" sound requires the front of the tongue to lift while the "CH" requires it to move down and back.
Or maybe it's the other way around like Chebbies.