We have an electronic combwhich kills the live ones.Vaguely amusing but takes ages cos they like to see the bodies.Just get a little beepy noise while you comb as it emits a small electric charge which kills them and traps the body..Stops when you catch one.You do it on dry hair,obviously and just avoid catch the top of their ears.I use that as soon as we see a live one.
I use the 10 minute lotion,Full Marks.Put it on dry hair,wash out in 10 mins.
Have found Vosene 3 in 1 helps as it has repellent.They also do a spray to put on after,which we did use for a while but it's all very expensive when someone else isn't checking their kid's hair and keeps bringing it back to school.
The cheapest way we got rid was just combing through with a nit comb and generous amounts of Johnson's baby conditioner,first a normal comb then the nit comb,just twice a week even if there's nothing there,you catch them quick if they do appear,and they tend not to cos the hair's too slippy for eggs to stick well.
Good luck getting rid,we don't have any at the moment,but having said that,I'm sure we will by the end of the week,souldn't say things like that,tempting fate.
Don't know why they don't just have a nit busting session every few weeks,if the whole school was done at one time they could really get it under control.
Itching now just thinking about the little beggars