As usual, Hamsters has provided a proper solution, so I'd never disagree with his scientific approach...
But your idea of just opening the bottle and brushing the stuff on fits the bill as far as I'm concerned, and if you're really worried, wear rubber gloves!
'R^&%$££$$$££""!!"£$%%a' just doesn't deal with 'Mind your own business' though, so a serious bashing with a sturdy Dutch hoe is called for! The weeds are just surfacing in our gravel drive, and I was only discussing the problem with Mrs Growster a couple of hours ago, but she didn't budge from her book...
(Er...what sort of rubber gloves, Brs B...? Are they the long slender ones which come up to the elbow, or the sort which just er, sort of cling to the hands in a rather tight, pale blue - er - 'nice' fashion..;0)