Baz it's been a while since I've done widefields with my Canon lenses but yes I have used my straps on them when I've imaged.
One night at the pony club I forgot to use the strap, set everything up and set the timer and away I went to chat to the other fellas.
Sure enough the lens dewed over very quickly and the frames were wasted.
I had a look and the 3" Kendrick strap is what I use for most of my lenses, like Eric said a little overlap is fine and will allow you flexibility as to which lens you use.
I don't have any photos of my setup, but I use a Dew Buster controller and my "hot box" to power everything in the field.
See this thread:
"Hot Seat"
