you asked if it was "okay", in the sense , I think, of not being cruel.
I would say there is absolutely nothing cruel to the horse. But you'll wear out your hand that way, and that's cruel to you. And, having each and every time you go forward be a battle can get old, fast.
So, using the end of a split rein, or a crop or whip (not spurs for a baulky horse and not unless you have plenty of experience). Do the Ask, Tell, Demand.
one soft asking with leg, one very firm telling with leg, and then Wham! put the whip on , and don't hesitate. it should have a a one, two, three! rhythm to it.
the horse will be surprised and will leap forward, or maybe crowhop, so you have to be ready and know that you can deal with this. Don't yank him back to slow again, just let him move out, even if he trots or canters, then kind of ease back to walk, slowly.
the idea is to make a BIG impression once, so that he'll remember that if he ignores you he gets a very unpleasant experience. he won't ignore you again.
that is less cruel than to have and everytime we go arguament with kicking, more kicking and slapping.