I believe they are called "enroute cleaners" and they have been there for some years now.
SUMMARY OF DUTIES:
En Route Cleaners (ERC) must be detailed oriented personnel who can follow direction and procedures. ERC are responsible for the cleaning trainsets while the trains are in transit (moving) between station stops. Primary responsibility for en route cleaners will be cleaning the restrooms with secondary responsibility to the rest of the train. The ERC shall perform the duties including but not limited to mopping, surface cleaning, and bathroom services. The ERC must be punctual, work well alone and at a fast pace.
ESSENTIAL FUNCTIONS:
• Able to follow all Amtrak policies, standards and procedures as directed by Supervisor.
• Physically able to carry supplies, bend, reach, etc.
• Report supply shortages to Supervisor
• Report maintenance issues to the conductor or train attendant
• Responsible for stocking their own cleaning kit
• Will make any announcements as specified
• Willing to work nights, weekends, and occasional holidays.
• The En Route Cleaners will be responsible for the following areas:
Bathrooms:
• Use cleaning products/supplies, as directed
• Empty waste bins
• Remove debris from floor
• Sweep floors
• Mop floors
• Replenish consumable items (soap, toilet paper, hand towels, deodorizer disks)
• Clean toilets, hand basins, and sinks
Rest of the Car:
• Empty waste bins
• When walking through the car, remove any trash on the floor or in the seat backs of
unoccupied seats.
• If there are spilled liquids on seats, wipe and dry seats
• If the vestibule is wet from snow or rain, mop wet area