I would stop the tissue and start teaching your child to blow their own nose. One way to do that is during bath time. This is a prime time to introduce the idea of what it feels like to blow air through their nose and how to do it on demand. Have your child put his nose just below the surface of the water and blow bubbles using only the nose.
Blowing out is a good option. Can try ear buds carefully with some vaseline gelly on