Myles & Andy R
I have had issues with the present blue Aerus Home Solutions bags as well. Either they get small holes near the bottom of the bag, or the blue sealing strip fails & dirt leaks out at the edges of the sealing strip. Bad enough, I decided to make a HEPA Cloth "liner bag" from a generic Kenmore 5055 HEPA Cloth bag to use with the supply of Home Solutions bags I have left. I would rather have my motor protected & the better filtration the HEPA Cloth bag would provide.
One way you can improve exhaust filtration on the plastic canisters would be to use the HEPA exhaust filter the Guardian Ultra used. It will be a tight fit into the hole for the filter & to use the vacuum as a blower, but if needed you can trim the foam around the tube. While the earlier plastic canisters, like the AP 100/200/280, Ambassador, Diplomat & Epic 6000/6500, may not be fully sealed like the Guardian Ultra, most of the air does go thru the filter & it's only slight leakage occurs. It's a nice little upgrade for any allergy sufferers out there that want to ensure the motor's carbon emissions are filtered out.
As for using HEPA Cloth Electrolux Style C HEPA Cloth bags in Canada, JohnnyVac, Hibbert & Tip Top Parts all offer their own in-house brands. I have used the JohnnyVac brand HEPA Cloth bags in my Grand Marquise with good results, & would buy again in a heartbeat.
Rob