It's the dratted 30 day clean. Day 10 has instructions that use Oxyclean. I think that could be an American brand. Tesco have Oxi Powder, which is probably the same - a powder that has a bleaching action and stain removal for laundry. Here is the challenge. Do I buy 500g for £2.20 or 1kg for £3?
The same product, Tesco Oxi Powder, is £4.40 per kilo if I buy 500g, but only £3 per kilo if I buy a 1kg drum. So buying 1kg is cheaper if you look at it as price per gram. However if I buy 1kg of Oxi Powder instead of 500g I will still have spent 80p more. I suppose I could look at it as if I buy one 500g pack of Oxi Powder for £2.20 and get the second for 80p, and both in the same pot.
I have washing soda in already and I am not in a hurry to build up cleaning supplies. I'll get the 500g pot and save 80p. It isn't a common requirement, and I don't think I'll use it quickly.
The next expenditure on the 30 day Clean may be a vacuum. The author seems to assume a lot of different attachments and flexibility. Mine has no attachments and I am happy about it. I shall worry about the problem when I get to it.