And for those trying to suggest that an empty leg out to pick up pax is technically a PVT operation, remember that the now empty Jerry Can is a DG that you will need approval to carry and need to manifest on the way home with pax.....
to send dg on a commercial flight you need to have completed an approved DG course.... 3 days of excitment!
From memory you can have upto 5L of avgas/petrol (don't quote me on the 5L... but was something like that, which would cover your 'empty' jerry cans) on a commercial passenger carrying flight as long as you have the appropriate paper work completed by a approved person & the PIC has handling instructions / precautions (MSDS)