There are a few posts on this, but back in 2012, what is the current situation, it seems like a great opportunity for them to say you have to have this stuff, here is a tiny sample, a bottle costs $X...
Still unlimited samples?
Is it possible to buy the right stuff in a local shop?
We have a toddler so mum will use lots!
(When I went diving in the barrier reef, we had a marine biologist along making sure we did not break/kill anything, when asked about sun cream he said, it did not matter, the bugs in the water would have it off in seconds anyway.)