i think worming is complicated.
to start with, its a given that all of your chickens have some worms. usually they can deal with a "normal" parasite load.
when you start with chickens, assuming your run/coop is on ground that hasn't previously had chickens, your flock can probably do fine without doing any worming, assuming they are healthy
however, as time passes, the cysts/worm eggs on the ground increase and the worm load gets heavier for your flock.
That is why many people practice once yearly or twice yearly routine worming with a chemical wormer. Nothing wrong with that - you do lose 14 days of eggs, and you can't do it when they are molting as it interferes with feather development.
the chemical wormers make me a little nervous, so I avoid them, except when I have an ailing hen. When I dont know what is wrong, I might worm just in case, based on what I am seeing with the hen. Now that I know I have mareks, I probably won't be doing that since a symptom of mareks is failure to maintain weight, which is also a symptom of worms. I probably thought I had a worm problem when it was mareks.
You will read that DE, pumpkin seeds, cayenne pepper, etc will act as wormers. I have not found this to be true. I do believe they assist in making an environment that is less supportive of wormers, but they will not resolve an overload of worms.
I do the soapy water thing as mentioned before. I can't tell you positively that it works - I haven't had fecal floats done. But I have had the flock on the same ground for 8 years at this place, and I am not seeing problems.
I did see some worms before I kept up the soapy water thing, and I used an herbal product that goat people swear by. Molly's herbals
http://fiascofarm.com/herbs/wormer.htm
I think it is a really great product and definitely works - based on fecal floats before and after that others have done. I would use it again if needed. It is a two part process and it supposed to be ongoing - a heavy dewormer followed by routine herbal support. I think there are other herbal wormers out there too.
Lots of different ways to handle worms.