We buy K9 ADVANTIX from our vet and have had NO flea/tick problems. It also is a mosquito deterrent for them, which is important, re Lyme disease and heartworm. We have tried over the counter products and found them wanting. Buy from your vet on this one!
It's not cheap, but if you go the less expensive route and get a flea infestation, the bombing and cures bring those expenses right on up there!
Fasteddie, I'm surprised the groomer found it necessary to shave Yoda for fleas. That's a bit extreme, in my humble opinion. A good flea bath would have killed all the existing fleas and gotten rid of the eggs. Poor Yoda! You give that little fella a special kiss from me -- and then go to the Halloween store and get him a fake mustache until his grows in!