[Bud Cline]

You'll be fine, just may have to use a little extra effort to fill the smaller joint but it will fill in with the soup as you clean the grout.

Even though the claim is readily made that "matching caulk" is available the truth is the caulk probably won't match perfectly and the texture will be different so I wouldn't suggest you use the caulk to fill a grout joint. In a corner where there is a change-in-plane the mismatch would go unnoticed but on a flat plane it will likely show in contrast to the grout.

 

[Bud Cline]

After the grout has been spread and set for a few minutes you will use a damp sponge to scrub and dress the joints. The sponge will begin to pick up some sludge and this sludge will easily fill the narrow joints for you.

 

[Bud Cline]

People use Popsicle sticks, tooth brush handles, broomsticks, god only knows what people come up with. There is nothing wrong with any of that I suppose but it is all totally unnecessary.

A simple damp sponge will do all of that in a whiz and deliver perfect looking joints every time. I don't understand why so many people try to re-invent the wheel all of the time.:wallbash: