Where I live and ride there is an awful lot of hedge cutting goes on by the farmers, I also rid off road quite a lot. I slime my tubes and it does make a difference, last time I cleaned the inside of my tyres the slime had fixed 7 punctures. So I would say I am happy with it. On a recent Robin Hood ride, I started off at the same time as a stronger younger rider than myself, at the finish I was 1 hour in front of him, he had 3 punctures on the ride, so I asked him why he did not use slime, his answer was he did not want to carry the extra weight as it would slow him down, DOH!.
I think we use something called Stans at about 50 to 75 grams per tube.
This I must add was when we were using tubes on mountain bikes.
I still use slime on the road bikes, although I still follow all normal procedures to try and prevent punctures.
Herzog, smokeysmoo, in which way is slime messy? once it is inside the tyre I have never seen it again, mind you I have only been using stuff like this for 20+ years so there is always time.