No, the bags are not flushable, they will clog the plumbing, do not flush the used bags.
Yes, you can dispose of them in the regular garbage. However, it’s always better to use a disposal method that will not go to landfill. A local compost collection bin or a specific bin for dog waste disposal is ideal. Landfill sites will slow the process of decomposition so it’s much better for the environment to avoid placing compostable waste in landfill.
The best way to do this is through composting. However, you cannot use this compost for any edible plants. You can also speak to your local council about what industrial composters are in the area and if they accept dog waste. A third option is to use a dog poo wormery to compost the dog poo for use on all non-edible plants.