Except homeopathy isn't cheap. Six bucks and upwards for a small bottle.
Cost of a bottle of mint solution? Bulk purchased through the NHS? Probably under a buck.
Firstly, those almost certainly weren't homeopathic, just placebo. Mint pills are cheap; homeopathic 'medicine' isn't.
Secondly, (IIRC according to Dr Phil Hammond, on HIGNFY some years ago), new rules prevent GPs from dispensing mint pills and liquids as placebos, which is a terrible shame.
qv the Bill Hicks routine where the waitress asked him "Whut yew readin' for?". Took him a moment to realise she hadn't asked what was he reading, but what was he reading for...
According to the back of this envelope:
660000 oil barrels spilt = 104931615 litres
At 17500 l/m = 5996 minutes.
At 24 * 60 min/day = 4.16 days.
So just one of these collectors could have hoovered up the entire spill in well under a week in perfect conditions. Even 10% of efficiency is still only six weeks. Even 10% efficiency and only working in daylight is still only three months.
Two percent of zero is almost nothing.