Hi, sorry to reply you late.
My tank has less 渦蟲 than before. I still use the same strategy. Feed my shrimps less.. maybe twice a week. The portion is reduced too. Everytime I feed the shrimps. the food would attract the worms. Then I will use the "suck thing (originally is for feeding medine for my kids) to suck those worms. Suck as many as I can.
No other ways for me so far...just need to be patient
Now I start to see my tank have some small shrimps , and now their survival rate is better than before~