Possibly a shallow tray & some petrol & roll the filter & agitate it in the petrol. obviously no smoking. Seen this done on a few cotton filters when no better cleaning fluids available & they cleaned up ok.
Once dirt & oil has been lifted out you can wash again in warm soapy water then rinse well & let dry. Do need use a quality filter oil & not to heavily applied or the maf will pick up to much oil residue.
Once dirt & oil has been lifted out you can wash again in warm soapy water then rinse well & let dry. Do need use a quality filter oil & not to heavily applied or the maf will pick up to much oil residue.