Is anything REALLY effective against dog ticks?

Hi!  New to the discussion group, would like to hear what others have to say about preventing/treating ticks on dogs.

We've taken our two German Shepherds with us before to France, Germany etc and suffered a bit with ticks, even though we've done the Frontline/Spot-On treatment prior to going.  This year, however, we went to Luxembourg over Easter and three weeks later we're still finding bloated ticks which have fallen off the dogs in the house.  Yuk!

The vet's receptionist told me I should be treating the dogs once a month, which I don't want to do, because after all it is a poison which the puppy could easily lick off the big dogs.  I thought these treatments were supposed to protect/treat the dog for about a month - easily long enough for us to take a holiday.

So far, touch wood, we have seen no infections resulting from the dogs getting ticks, but it feels rather like Russian roulette.  

What do other members do about ticks?  The dogs have such a lovely time on holiday, but I would feel guilty about taking them if they became ill, either thro infections from the ticks or overdosing on the various powders and potions available to treat them.