How do I deal with knots?

[Bertiebassett]

Our Coon, Monty, is 12 months old and over the last 3 months or so has developed some awful knots in his coat. We comb and brush on a bi-weekly basis, but his coat has got worse, so much so that we are considering having him shaved.
Are there any tips out there for keeping the knots down?
Should we get Monty shaved and start again with the combing?
Are there any products that will keep his coat knot free (like a conditioner)?
When will he lose his kitten coat fully and will that stop the knots?