Scotchgard is a good product but Scotchgard does not repel any dog hair or any other pet hair from clothing, furniture etc.
The Scotchgard does protect your furniture though from spills, stains and pet messes but it will not repel any dog hair.
If you have furniture that you want to keep pet or dog hair off of you either need to keep the dog or other pets off the furniture or use a plastic cover or a washable cover on the couch or other furniture.
That will protect your furniture from the pet hair and other stains.
Once you get pet hair on upholstery it can be very hard to get all the pet hair off.
But you can use a lint roller to remove some of it and also use a brush or small broom to help brush off the pet hair.
Then vacuum the upholstery.