I doubt you will do better than Dynorod. They may have their faults, but they do have the kit. A pump-out tanker is not going to be of help in removing the blockage, although it could pump out the flooded manhole/inspection chamber. This would be an expensive way of getting a day or two relief if it's a small chamber.

Having dealt with a couple of these at my son's house, I suspect the blockage is at a buried pipe junction, or possibly a broken pipe. In either case, if the blockage can't be jetted away, excavation is the only answer.

Phil