I consume countless 10L DEF plastic jugs that would work very well too. If this is something we are going to really do I can start saving them at work.
I think the $ value and cost is a reason why you have to do it.
At Shannonville we fill about 5 bags a weekend [equals one section of air fence]. Now ,we can use all bottles, but mostly all the bags are filled by people bringing stuff from home.
Air fence is so expensive and demands so much attention. Think about it this way and using 40-48 inch bags. Air fence is about $7000 US for the last price I have. That would be 25 foot section. Compare that to the cost of 6 bags at $20, $120.
If someone wants to look for bags out there, you may get them cheaper then us. we are using a guy in New Brunswick who is keen on helping. But shipping may be the big issue.
The guys in Nova Scotia, Shubie,, can not use water bottles either. So they use milk jugs,windshield washer jugs etc.
I'll see what we can do from this end to help. But once you get started it is seriously hard to keep up. This is something every rider,fan,crew can get involved in.
Good luck.
John