When I moved into this lovely wooden box on the hill I noticed the previous owners had applied some caulk-of-desperation in both of the showers. The fundamental problem was that the tile job had not been done correctly, and applying caulk overtop of it haphazardly had really not solved the problem, just caused new ones.
That said, I'm not in any mood to replace the tile just yet, but replacing the caulking the right way is at least going to hold things together for a while.
I picked up a tube of sanded, colour-matched caulking that promised to blend in with the grout, and buttered up the joints nice and neat.
You can still tell it's caulking, but the sand in it really breaks up the usual bright glossy white shine and makes it stand out from the grout a lot less.
I've got half a tube left so now that this shower has cured and survived a test run, I'm planning to give the other shower a once-over as well.