A good and easy way to soften paper towels is to get them damp with a bit of water.
You could soak a rag in some water and then place the paper towels on the rag to get the paper towel damp and softened.
Or you could place a roll of paper towels in a room with some steam.
Or spray the paper towels with some water to soften them.
Although paper towels don't break down as easily in water as regular toilet paper does the water does soften the paper towels some.
You can also use paper towels for toilet paper but just don't throw the paper towels down the toilet as it can clog the toilet up and clog your pipes.
If you do need to use paper towels to wipe your butt in place of toilet paper just make sure to throw the paper towels in the trash when done.