I have a shower that has a tile floor and walls. The tiling on both the floor and walls seems to be ok except for cracking of the grout in the corners, mainly walls to floor. It appears that someone previously tried to caulk the corners but did a very poor job. I have removed all of the caulk and any of the loose grout. The question is should I grout the joint or use one of the tile and bath silicone caulks, like the GE silicone II, to fill the corners? Thanks for your input.