The problem of twisted sheets
can be from many sources - but many a time it has to do with the core
of the line being used. A line with a stranded core
will tend to twist under strain, and continued strain will 'iron in ' the twist. It's actually an easy fix - on most blocks, the swivel has a small set screw which locks the swivel in place. Set those in and 95.875% (scientifically verified) of your problems are gone.
As far as a traveler, I think alot depends on boat size. A school
I work at has Catalina
25's with travelers that span the cockpit. In a perfect world, these would be good for dumping the main, as most books
tell you. In reality, the cam cleats
have been stepped on and the mounts are bent, so it is nigh impossible to cleat the traveller under pressure. The mainsheet, meanwhile, is right there and on a cam, so it's much easier to just dump it. The vangs aren't too powerful, so I just crank on the main as much as I can, snug up the vang, and then re-trim the main.
Remember the two rules of sailing:
1. Always look good (and yes, this goes beyond sagging headsails and screaming at your wife when docking
; it includes the obvious like not falling overboard).
2. Don't do any work you don't have to. Does the dodger
make it a pain to use the traveler to dump in a gust? Hell, man, just use the wheel
and feather up a bit - that gust will pass, and then you don't have to set down your beer