Pickng up litter is something that could be ordered and supervised and they pick up more and longer if they mess up.
I would ask for a letter of apology and financial restitution. You can probably get a phone estimate from a cleaning company in these circumstances.
If they damaged someone’s car finish or stained the siding on someone’s house, they could be in for a very nasty surprise.
Next time they should stick to TP.
I think toilet paper is harder to throw. Hard work is not in their book.