yes, get one. they have grooves which slice the eggs off the hair shaft, plus the teeth are closer together, so they really do get everything out. go to the nitty gritty site and there is a link to some info about getting one on prescription.
Agree, worth every penny! I messed about with other things and heard about Nitty Gritty on MN - was horrified at the first use at how many it caught, but cleared them out (with Hedrin too) over a couple of days.
Nitty Gritty and conditioner is really all you need to deal with nits. Forget chemicals and forget plastic little combs that often come free with the chemicals. They sail past the eggs and often don't even seem to budge them.