A professional clean and check will not only make the instrument look beautiful, it will also improve the tone and projection of your instrument.
By playing we deposit bow rosin dust on the top plate of the instrument (and inside it too). A build up of this dust layer will have a negative effect on the tonal qualities. Besides that the soundholes can build bridges and this ruins sound and overtone capabilities.
If you are interested in having a go yourself, I do offer my polish in handy little bottles in the accessories section.
If it is empty and used up, just send it back and I can refill it for you!