I've used gasoline to clean those type filters. The shop manual for my '56 Cadillac recommends gasoline or kerosene.
I slosh it around until it's fairly clear running out and then I let it dry/evaporate in the sun before oiling it. The 1948-'52 Chevy truck manual says to dip it in engine oil after the solvent is dry. I think any viscosity will be fine.
The description of the filter element refers to it being "saturated in heavy oil" so 50 weight is probably just right.
Last edited by Otto Skorzeny; 01/17/2022 8:05 PM.
