WRONG!
If you wait too long to have your carpet cleaned then you run a HUGE risk of having permanent damage done to the fibers.
Unfortunately though, this myth is based on some margin of truth… Some so called “professional” carpet cleaners will leave the carpet either too wet, full of residue, or both.
If the carpet is left too wet, soils are suspended in the excessive moisture and when it dries, this soil will soak back in and appear throughout the carpet fibers.
Always ensure that your carpet is cleaned by a licensed professional.
and ALWAYS ask for a Guarantee!