I pull Fred Archer's spider dredges with 12 hollow squids on 50# line(R-clipped low) and an 8oz sinker at 5k no problem. I snap the lead straight to the 50# and then the 400# mono dredge main line snaps to the lead. The bar runs about 2-3' below the surface. I'm sure I could go 10k+ with a 16oz sinker or deeper at a slower speed. I have the chase bait rigged to break free of the dredge on a seperate r&r to fight the fish. I could fight the fish right off the dredge but i'm paranoid about losing it. I can reel it in one handed without taking the rod out of the holder. It's not a huge umbrella size dredge but with a meatball bar right above it i've got at least 28 teasers within 4' of vertical distance and that's just off one short corner.
I'm no fish but that underwater video of the Archer spider trolled behind a cigar sinker just didn't look too natural to me. The idea of using a lipped lure as a "sinker" in front of the dredge makes more sense.
I experimented with the rigged Mann's plugs, I found they were prone to tangling and exerted allot of drag pressure. The Stretch 40+ was plenty to get a dredge down, I feel the Stretch 50 is over kill and costs allot more. What is nice is the vibration it sends to the dredge and they are very easy to rig yourself with a three-way swivel and cable.
As an alternative to the swimming plug and/or standard dredge weight is our new Rubber Coated Dredge Weight. They are through wired, solid lead, and have our exclusive heavy duty rubber coating, available in Blue/White and Black/Purple, both rigged and un-rigged. Approx. 9-10" long.
Remember the whole idea behind the dredge is to attract fish to your boat, if you can't see the dredge you can't see the fish. I generally tell people to fish the dredge 15-20' behing the boat and 3-4' sub surface. Every boat fishes differently and many ways to fish dredges this is just a general guideline.