When I was doing my 125 mile a day commute, I encountered a number of nails/screws/etc. in my rear tire. (Always the rear!
Anyway, before
@Byron took off for Kentucky, I used the worms all the time. After Byron left, I had to start changing my own tires, and since I was hopeless at trying to balance them (Byron was a PRO!

), I switched to the ceramic beads.
There is a problem when you mix beads and worms in your tires.... After about 2,000 miles, I decided to replace a worm with an internal plug/patch. It was a good thing I did, because there was nothing left on the inside of the tire, of the worm! The beads, bead blasted it completely gone!
After that, I always replace the worm, as soon as I can. (When you are on a trip, the worms are great, so when I get home, the tire comes off, the worms come out and the plug/patch goes on!