I have a second filter so that I can take my time to wash, dry and re-oil properly. I try to always keep one ready to use. Drying times depends a lot on drying conditions. If you have it in the sun with a breeze drying time would be a few hours. Sitting inside a cool garage with no air movement drying time could be 2-3 days. I also like to allow a day or two for the oil to migrate throughout all the filter media. The extra filter is worth it as I am protecting an expensive engine.