how to clean air filters
solvent or such to cut the old oil, then hot soapy water to get rid of latent solvent, then hot water rinse to get rid of the soap, then air dry completely. Never blow with compressed air!
then proper foam filter oil is better than engine oil, then grease the sealing lip.
As stated above, keep a spare serviced and ready to pop in.
that's how I do it.
I have a no toil kit but have yet to use it. I keep doing it the old fashioned way.
'72 BMW R75/5 (Col. Klink),
'02 KTM 400 E/XC,
'05 ktm 125 sx (for sale)
"Hey, are you okay? Can you get up?
I thought you said you could ride"
All the best