I have been using those cheapest chain-tugs and they have been very reliable. (kinda cheap looking though)
I replaced the nut with wing nuts and that makes the pair even more useful. But end-guards (is that how they call em?) deform easily and become rather cheap looking. ... Then again, you could grab these by dozens anyways.
Probably don't matter but these things can go into the ends in crooked angles if you are not careful. This ticked me off, so I am using Tuggernut right now. ... But I think I am going back to the cheapo tug, soon.
P.S. These should not cost more than 5 bucks. Busine$$cycle's price is a bit highish. Note also, they don't work all the time, you can't pull too far. Also, if your wheel-base is tight, it might not be able to reach out. ...