I'll have a hunt see if i can find any decent test kits. Surprisingly hard to find over here, even on the internet.

I've had a quick look on the Tesco (Walmart equivelant) website and found the following:

+ Bleach:
I did look last year at quite a few places for bleach. The problem i had was finding just pure bleach. The nearest I got was 'Domestos Original'. Ingrediants
Disinfectant: Sodium Hypochlorite 4.8g per 100g,<5% Chlorine Based Bleaching Agent ,Non-Ionic Surfactants ,Soap ,Perfume. This sells at about 2 litres for £2.50/$4.

+ Washing Soda:
Soda Crystals in the UK. "Contains Sodium Carbonate Decahydrate greater than 30%". Sells at £0.90/$1.50 per 1kg.

+ Baking Soda
Bicarbonate of Soda. Sells at £1/$1.60 for 0.2kg from Tesco. Amazon UK sell it for £5.0/$9 for 1kg

+Borax
Can't find it after a quick search. Looks like i can get 1kg of Borax Powder (Decahydrate) from Amazon UK for £8/$13. Or they have "Household Borax Substitute" for £4/$6.5 for 0.5kg.