The 9th house is the house of religion, philosophy, and preaching. Rahu is the planet of illusion and outward appearances.
When Rahu sits in the 9th house, it creates a highly hypocritical personality. Dr. Sharma points out a funny but accurate *Nishaniya*: This person loves to give long moral lectures ("updesh") to everyone else, but they never look at their own flaws.
Physically, they will dress impeccably, always looking shiny and perfect ("lishka mushka rehta hai") for the outside world. But if you look inside their actual house (or their inner mind), it is a complete, dirty mess. Dr. Sharma advises them to stop preaching and start cleaning their own physical and mental "house."