On my last trip, my travel companion was hanging out with some people she met. The group tried to entice me to go with them to see the croc feeding. Of course, I refused and I asked my friend to please, not go. I explained that it was illegal and was trying to explain why it's a bad idea in general. A local that overheard this conversation, began to chastise me for taking food from the mouths of those that feed the crocs for show. He went on explaining that sometimes the crocs get under people's houses and it is the croc feeders that entice them out. Then he started to rant and rave about Steve Irwin . . anyway, I couldn't follow it all.
I told him that if the practice were completely stopped, the croc feeders would find better work.
My friend almost never listens to anything I say and so off the group went to look for a croc feeding.
I explained it to her again later and then she went "Oh!! I didn't realize. If I'd known all that I'd never have gone." Sheesh.
So, yeah, charge the tourists too. Perhaps print up some flyers about the negative aspects of the practice with emphasis on the illegality and what the tourist(s) could be fined. Then have the flyers distributed to each room in each hotel.