I have been using a Scalibor collar on Charley since they came out. I used to have a holiday home in the Midi-Pyrenees, where it was rife with ticks, and never saw one on Charley. We used to stay there for up to six months, until I sold up two years ago. Went to France in the caravan this year and bought Scalibor collars for Charley and Henry.
In all the years that Charley has worn one he has never had a problem. Nor has Henry, and they are still wearing their collars as they are effective for up to six months. Take no notice of the scaremongering. I certainly wouldn't subject my dogs to anything that might be dangerous. Ticks and sandflies are more of a danger than a Scalibor collar. Incidentally, they are no longer POM and can be bought online, much cheaper than the vet used to charge me.