Having come across this S&S video showing how to clean and oil your air filter , I thought I would give it a go.

https://www.youtube.com/watch?time_continue=10&v=aln1-EYtfVk&feature=emb_logo

I have to admit I have not done this for a good while , and was amazed how much sand and muck came out as I rinsed off the soap in the sink , as per the video.
Certainly not stuff I would want entering the engine , showing the filter is working ok.
Before I washed it I could see some small areas were blocked, but was gobsmacked how much came out during washing.

The steps show in the video are :
1 Shake off any loose debris
2 Apply some liquid soap ( I used hand soap from a dispenser) to loosen the grit and grease and leave to stand for 10 minutes.
3 Rinse the filter off in warm water and watch the muck flow down the sink.
4 Air dry completely.
5 Apply filter oil - essential

A quick job to consider before hitting the road again?