Hydralyte via the collect20 deal with ebay, these are the tablets in the listing, sachets and premixed solutions are also available.
I find hydralyte very effective at hydration and it is also palatable. It's not the cheapest option, but there are few if any better options. The price is okay I think, its the best that I could find.
Regards
Cheaper to go through Amcals website than ebay store..
$22.95 + Use code Yes for $2 delivery.
$25.86 from ebay vs $24.95 from website.
Can also use code STORM for an extra 10% off.
BINGO for free shipping when you spend $40
Or if you want to save the extra $2, you can click and collect for free through the website, total of $22.95