Has anyone used one of those apps that *can* improve the sound of the diiirty speakers on your mobile phone?

Er, the one I used called 'Clear Speaker' actually worked. Instead of my audio being shockingly crapper than crap, it is now just crap, but a lot less crap then before.

It plays various tones designed to dislodge dust and gunk in the speakers, with shaking optional. Wish I had found it earlier actually.