I bought in bulk at 18 quid for 25 litres at 15% juiced down 4 parts water to one part solution. (Walker Bros, Oldham)
You're right about it bleaching clothing/shoes out, no bother.
I brush it one my drive with a long hair soft sweeper, leave it 20-30 mins then rinse it off with a jet wash, looks like new on completion.
Would wrapping it in clingfilm assist?
That is what I do with oven cleaner - brush it on to the sides and cover with cling-film. Way better as it stays in gel form.
for the oven roof - lay out alu foil, with cling film on top. brush the gel on to the oven roof and offer up the clingfilm/foil. drop the foil out and pat the clingfilm on to the surface.
The foil is just to support the clingfilm as you lift it into position.