Chain cleaner: is it a big con?

[b1k3rdude]

Like bottled water, I feel that paying upwards of £7 for only 400ml that dosent look like it will last beyond 3-4 uses is a complete rip-off.

I am convinced that I/we can get the a bigger quantity of same chemicals/solvent that will do the same job at a fraction of the price and not damage the o-rings on our drive chains.

Does anyone know what the ingredients of the most chain cleaners are, or failing that a diy alternative that will do the same job.