The offer of spend £23, £28 or £35 to receive a free gift has been posted before, as has the glitch (see below if you don't know what it is).
However, I have discovered that you can combine this glitch with their '50% off Spa Wisdom Pamper Collection' and you get £64.50 worth of stuff for £20 plus Quidco!
Items included are: Spa Wisdom™ Morocco Scrub – 200ml (RRP £12.00), one Spa Wisdom™ Morocco Finishing Mist – 100ml (RRP £8.00), one Spa Wisdom™ Japan Bath Salts – 400g (RRP £12.00) and one Spa Wisdom™ Japan Shower Gel – 250ml (RRP £8.00) for a total price of £20.00 instead of £40.00.
In addition, add the code BODYSHOP5 for £5 off. Seems to only work when you spend about 27. I did all the free gifts, then added the Spa Wisdom items, then added 3 cotton wool bags, applied the £5 off code and therefore effectively got 2 of them free since they are £2.50 each.
The glitch is add the all the free gifts: a shower gel, body lotion and body butter to the basket at the beginning and you don't need to spend the above amounts to receive them for free: add £20 or more worth of stuff and on clicking 'update' next to the free items enough times and with some trial and error, you can get them all free without having spent the qualifying amount).