So many variables here. Each coach manufacturer dictates the canister and filter, as well as it's placement. So an ISL400 in one coach, can have may different items with in the front end breathing plumbing when compared to another ISL400 powered coach.
Also, search under Cummins forum, for posts from Spike45. He is, IMO, one of the most knowledgeable members in regards to flirtations of any kinds. (He worked with Cummins/Fleetguard until he retired - and knows of what he speaks
!). Spike45 cautions about too frequent of Air Filter changes. A new filter, is letting in more particles. The actual partial clogging of the filter cartridge, adds to it's ability filter better. And, each time you open the front end of the breathing pipeline, you risk contamination, and 'dusting'.
Also, IMO, blowing out a cartridge is never a good way to go. Too easy to damage, and that is damage that you can't see with your normal vision, the cartridges materials. Just not worth the costs of trying to skimp by cleaning out and reusing.
Now, that being said. If I had an unusual sittation that caused severe dirt accumulation on the air cartridge. And I had no way to replacing it. I would remove it carefully using best practices to eliminate dusting risks, and tapping it to remove external cartridge dirt accumulation. (Look for some sites that reflect this, and how to slowly turn the filter as ou are tapping it at about a 45 degree angle. Keep doing so, until you are not seeing dust exit the filter. I was told if you had to do this, to have a shop vac blowing the dust away from the filer in general.
And Rider Fan, I here you about dust build up! Especially with air canisters and or intakes, that are low and behind the rear wheels... Makes you think about the rest of the design, when seeing this configuration
Best of luck to you, and suspect you will get other input on going ahead and changing an air cleaner as frequently as you feel is needed. Not sure that tis solid advice