Your older dog might be past the point of taking long walks outside or heading down flights of stairs to get to the backyard to go potty. Or maybe you have an older dog who can no longer hold his bladder while you are at work and away from him all day. If you and your older dog are dealing with any of these things, it might be a good idea to protect his dignity in his old age and train him to go potty on indoor grass inside your home. This gives him a safe place to go inside without punishment or humiliation. Indoor grass also gives him the same look and feel of the grass that he has been using outdoors for years. Training your older dog to use indoor grass to go potty will alleviate a lot of stress for you both.
Training your older dog to use indoor grass is giving him permission to go potty inside without consequence. If he's at an age where he can't hold it as long as you are away, giving him this permission to go indoors will be a huge confidence booster for him. Be sure to keep the indoor grass in one area, so he only has the idea of going inside without consequence to get used to. Training your older dog to use indoor grass doesn't take very long. Be patient and offer lots of rewards and verbal praise, so he knows he's making the right choice. Indoor grass works really well for small dogs. Larger breed dogs can also learn to use indoor grass, but even in their older age, they may require some outdoor exercise every now and then.
Depending on the size of your dog, you can get boxes of grass pre-made, or you can purchase strips of indoor grass and set them in areas you are permitting your dog to go. You may want to walk your older dog on a leash to this new potty area within your home until he gets used to the permission to use it on his own. Be sure to schedule some time showing him this rather than put it in place and expecting him to know what to do with it. Also, have lots of treats on hand to reward your older dog and ensure what he's doing is okay.