You know, that suction canister looks expensive - I would take an old peanut butter jar and drill a couple of holes in the lid with a spade bit. Get a couple of rubber grommets from home depot and the tubing should form a tight enough seal.
I do the "trick rope" cowboy thing with my 10 ft tubing as well (word to the wise, don't do it inside).
DIY suction canisters could save costs, but I'm sure there are "non-medical" suction canisters out there--I just don't know if they go by a different name or not. Generally speaking, anything "scientific/laboratory" or "medical/dental" means it costs at least 10 times what it should.
You must have a good seal throughout the system if you want to "dehumidify" the hoses in an efficient manner. I'm not a HVAC specialist, but, from what I've been told, water vapor can pass through just about any opening or material unless it is truly airtight and impermeable to water vapor. A close fit or casual seal isn't going to do as well as a truly air-tight system that's blowing warm dehumidified air through the tube towards a dessicant like damp rid. This minor point would be more of an issue in hot, humid environments like Florida (where I live) than, say, Southern California.