silicone adherence to unglazed tile

[squowse]

I am renewing the tiled surround to my roll-top bath. I have small strips of tile glued to the top of the roll-top. the previous silicone debonded from the unglazed tile edges. Maybe because the joint was a bit small and couldn't handle the movement. Although i planned the movement to be in the joint between these tile and the wall tiles.

I was wondering if I should prime the edges with something to help the silicone adhere, or if I should be using a particular type of silicone? I was planning to use "Forever white" and I used something similar before but Unibond.

 

[lancenotalot]

I always use dow corning silicone,clean the surfaces thoroughly with spirit before resealing