sonic combs for cats

[poppysix]

I have a stray cat that I think has flees, I have tried to dust it with flee powder but it just runs away and I dont see it again for a few days has anybody tried one of those sonic combs that I see advertised, does it work and will it not hurt the cats hearing

[Greedyfly]

I have never heard of them or seen them but why not just get some of those flea and tick drops from Frontline or similar company - all you have to do is drop them ion the back of the neck, job done.