This thing might work with a very low vacuum, definitely not for an engine then. It has no hard frame to support structure, it'd flex and leak air very badly.
Construction quality is also very poor; look at the side pasting, filtration media doesn't look any good either. Looks like it's made in Badami Bagh, Lahore.
No it's certainly not washable, not if you need your engine any more at least.
I have yet to see a single quality product from Leppon, apart from their marketing scheme.