Back about 2-3 weeks ago this news group pointed me in the direction of
using a tile grout 'colorant' to rid ugly grout stains within the tub-shower
enclosure.

I got the product from Home Depot. After degreasing the effected areas I
sat down on the edge of the tub and started painting grout line with an
artist's brush. It worked wonderfully!!! The only minor drawback was that
the newly treated areas looked so much better than the non-stained portions
(which were to be left as-is), that the project expanded about 2-fold.
Overall I did everything up to about waist high at the front and long wall
of the tub. The back wall was in pristine condition and I left it
untouched.
Thank you group!!! Great advice.

Ivan Vegvary