Has anybody tried this gizmo (Harbor Freight vacuum gun, $10)? My buddy picked on up for me and I used it tonight. I was impressed with it. I used it to remove ash and clean the tubes. The gun has a 1" suction port that I extended with a 36" long piece of 3/4" PVC pipe. Compressed air is used to create the vacuum and the output side goes through a flexible hose into a collection bag. I think I will make a 5 gallon bucket to replace the bag. I have used a shop type vacuum in the past but the filter will plug with fine particles and loose power or stuff get stuck in the hose. This machine is just a straight shot no filter to plug or places to jam up. Pull the trigger and the gun sucks up the ash. I slid the PVC pipe down the tubes and in areas around the refractory, rather nice way to clean without the need to climb into the boiler. I can clean the tubes in 2-3 minutes. I suppose a water filter could be rigged up by leaving the lid on the bucket and exhausting into the water, then the water could be dumped out. I will give that a try.