According to chap in shop the company are still testing this stuff out and thats why they arent making big claims as being a weedkiller because the odd type of weed isnt affected by it and thats why they cant say it acts as a weedkiller as such.
But if it does what they do lay claim to, then im game to give it a try as it really frustrates me when you see a drive youve cleaned only a few months doen the line to see weeds again. Obviously customer hasnt taken advice about looking after drive once ive cleaned it and so these sould hopefully be more inclined to pay for a care package perhaps