Unless the grout is coming out, nothing special needs to be done to
the tile. Just make sure you clean the part you'll caulk over, viz, at
the joints.

What about the tile itself? Did you do anything special to it, or
perhaps you don't have a tiled tub/shower?

If you do, did you use any particular sealant on the tile, and does it work?

--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16