Air duct cleaning questions

I keep the duct cleaning equipment in the van only because I do not have a convenient location to store it when not in use. My price point $25 for supply vents and $35 for returns. Don’t forget to charge for cutting or drilling holes and taking of ends of the trunk. There is a big learning curve. There really isn’t any real good tutorials of the ram air system. Don’t bother calling ram air because he won’t return calls. Poor customer service also. The supply ducts off the main trunk are fairly easy and straight forward. The supply main trunks are nearly impossible to clean if at all. Regarding the return system: #1 clean the filter first, then use wide masking tape and tape all but the furthest return vent in the house. This will give the furnace the most suction. Vacuum the opening and anything that can be reached. Use the black hose without a air ball. The hose is real stiff and can be hard to maneuver. Blow the vent several times. Replace and tape the grille and move on to the next one. Check and clean the filter halfway through if needed. They do clog and then you have a mess. If possible remove the end cap off the main return trunk, blow it out also. You may have to drill a hole to blow out the trunk at times and then use aluminum tape or a plastic plug to cover it. Clean the area where the trunk meets the filter. Lot of build up from the cleaning will occur. Make sure all the tape is removed. In my opinion, the ram air system isn’t that great. It works but there are issues, not able to clean supply trunk being the biggest one. If the supply ducts have an inline damper, the duct ball will get stuck in them. If it does, then you have to take things apart to get the ball and blue hose out. definitely a PITA. I turn down jobs that have a lot of heavy stuff in them and if there are lots of trash and dead mouse carcasses. if I cannot do it right I do not do it. They do not want to move well and can get stuck. Take the lights out of the plastic hood and keep them in the box. Do not use them or they may disappear down the supply vent, never to be seen again. If you need a light, buy one that straps on your head. For dryer vents it is great! Clean the dryer first as there is a ton of lint that builds up in it, give it a good blowing out with the dryer running on air fluff. There ya go, quite a rant but the basics in my opinion. I hope it helps. It is not comprehensive at all. I’m sure there is someone else that hopefully will share their experiences also.