
It can take 24 hours to kill the fleas on the dog, and of course unless you treat the environment new ones will jump on, so you may continue to see live fleas until the frontline works to kill them.
I would not use antoehr treatment on your dog, until this one has worn off. Hibiscrub is an antibacterial/antifungal wash,a dn it shoudl help prevent skin infections caused by his scratching.
The majority of the fleas live in the environment, so that is where you need to concentrate your efforts,
spray the house with a household spray that has an insect growth regulator, RIP, Acclaim etc.
As for hedgehog fleas, they may jump on but can't live on dogs, they are Host specific.
The most common flea on cats and dogs are cat fleas, as they will happily chomp on anyone, including us.