Darren, this is a political term. When those standing for a particular constituency do their junk mail distribution they have three distinct tasks. Firstly, the 'blues', who are virtually guaranteed to vote for 'the party', the 'reds', who are not, and the 'greens' who are most likely undecided (as opposed to being 'greenies'.) So, 'Gluing the Green Envelope' actually means sucking up to someone you don't know with the intent of influencing them to your way of thought.

Now, a young lady asked me this the other day and I was at a loss for words - in fact I was flabbergasted as I hadn't put the hard word at that time; help me please, what is a Dirty Line

One on which you cannot get a clean signal, meant either literally or metaphorically. A young lady so au fait with hacker slang sounds a valuable catch.

What goes on in the purple light district?

Very much the same as goes on in a red light district, but with additional farm animals. Mind your feet when you visit, and do not be surprised if you see a good-looking ewe in a shop window.

Paper CD?

And I hope you noticed that I said nothing at all about Welshmen or welly boots in that entry about purple light districts. Oh, bugger, I just pressed "Submit" by mistake....

A paper CD is an item of clothing (if it may be termed clothing) for suntanning the genitals, consisting of a circle of reflective paper with a circular hole cut concentrically in it. To wear the paper CD, you simply stick your (cough cough) through the hole, go sunbathing wearing nothing else. The sun's rays are concentrated on the key area producing a pronounced tanning effect. Just be careful you don't burn.

What about a dog-end brusher?