What does my friend need for a border bounce at Sadao after overstaying on a Non-B visa?

A friend is attempting a border bounce at Sadao after overstaying their Non-B visa and needs advice on requirements. They inquire if cash or a bank statement is necessary, and whether an onward ticket is required despite having a valid work permit and a supporting letter from their school. Comments indicate that Sadao is not the most accommodating border for visa bounces and caution that minimum cash for fines and possibly staying overnight in Malaysia may be needed.