1) Buy pantyhose & lint roller from dollar store for $2
2) Cut off toes of pantyhose
3) Put toe piece over intake fan
You now have dust protection and tool to clean.
Pantyhose, S3? Sheesh, this really is turning into miningpron. You need to post pics in the Pics of your miner thread.
If you need a finer filter on a fan that has a higher flow rate, used fabric softener sheets work well.