Finally got round to cleaning my K&N after *cough*15,000*cough* miles and what a difference! lol, well not surprising really, but anyone putting off this job...get it done!
Really easy actually, get yourself the cleaning kit (£12.99 from Hellfords) and its just a case of sticking on the cleaner and leaving it to soak. Rinse it, let it dry and spray on the oil. Job done! Takes about 30-40 minutes.