As for flight students, I think that OPNAV states you can't sign for a helicopter until you have 500 hours flight time - putting 2 students in the helo might be a workaround. Again, paging Jim123 for an answer....
The -57 is single-piloted, but really, are studs ever taught to fly it that way? I'd argue no, so why then send them on a solo by themselves? Besides, let's be honest, not every helo SNA is capable of flying solo to an OLF, let alone on a RI flight to another airport.