Don't use any heavy compressed air to blow out your filter elements! If you must, tap the element very gently (even tapping not recommended) and/or use a very low air pressure on an angle to the outside of the filter only, never blow from the inside out. Heavy knocking or banging or using high pressure air to clean the element moves fine contaminants further into the filter medium and then the engine. For the cost of a new filter, I wouldn't suggest heavy cleaning methods which contribute to engine damage, rings and cylinder sleeves in particular. Same for all filters, even drinking water filters cannot be reversed flushed. Look after you engines and don't skimp on this stuff. Also, how good do you think a washable filter medium is if you and wash the dust out of them and how much actually gets dislodged and washed out, in fact how good are they if you can actually wash them? I'd be thinking about it
Edit: As a suggestion I would sit well back front any leading vehicles and allow cross breezes to carry the dust away or wait for any dust to clear rather than driving in it. This will reduce the dust intake and in turn prolong the life of the filter. I don't think anyone could avoid driving in conditions where wind is whipping up dust and it's everywhere.