I've got some of those, too.
These guys don't have any "fan" part. Only a long, mucus-like string that they send out. When floating particles attach to the line, which is sometimes about 8" long, they reel it back in to the tube. Then the pieces it doesn't like, such as sand, are expelled back out. If I pass something like a chop stick through the mucus line, it easily breaks.
They strands are kind of annoying and unsightly, so I'd like to get rid of the critters without making the problem worse.