Hmmm. I wonder what sort of worms you have, nematodes or other. Chances are they are your friends.
If I was in your shoes, and they were really bothering me, I'd bomb it with a light dose of formalin (I'll probably get slammed for this suggestion)
If you dose your tank with 25ppm formalin (25ml per 1000L) and walk away it will probably kill the worms without disrupting the biofilter too much. I'd repeat the dose every other day, three doses of formalin in total. Increase the airation during the treatment and watch for ammonia and nitrites.
I've found, many many times, that a light dose of formalin will upset a biofilter less than a light dose of salt.
Personally, I'd leave the worms alone. They are eating stuff that you are not removing and doing you a favour. Probably great feed for your fish too.
Second thought - I bet a few cory's would smash 'em.