Best thing for lice?

[L&B]

Its that time of year and my poor blinkin 9mo filly has caught lice
The vets came out and used some pour on solution down her spine which for the most part has stoppedher itching (so must've killed off a fair few).
Going through her warm bits though with a flea comb I'm finding the odd adult and tonnes of eggs still
What is the best product/method to rid her now? She still has an infestation I would say, so something to rid a opposed to keep at bay...

She really is a beautiful traditional girly so I'd be vv reluctant to clip her since he cost itself and mane are in gorgeous condition...
Any kind help greatly received.

 

[hayinamanger]

Your vet has probably used Cooper's Spot On, it usually kill the lice in a few days and should be repeated in 10 days to break the cycle. It's very useful stuff.