I bought it to remove grout between my bathroom tiles. I broke one bit right away, while I got the hang of how to use the tool. Second bit cut fine, but it was hard to maintain a straight line. The concentration, not to mention the fine dust it produces, made me go to Lowes and buy an old fashion manual grout scraper. If you think you'll do the whole bathroom with this tool, forget it - it's not gonna happen.
The bit itself is decent, but the nature of this (bathroom) job causes it to break too easy. I'll probably use it for something else.

I started to use these bits for removing the grout on the tile above the bathtub. The bit worked fine for awhile, then it broke. I purchased several more of the 1/16" bit and even tried the larger one. They heat up and break. They are not cheap to replace. I found better bits at leakyshower.com for a fraction of the price. The dremel bits work, yet are not worth the cost. Maybe next time I'll just scape out the grout by hand.

This bit cuts very quickly at first but breaks rapidly. This works fine to replace a broken tile or two but isn't for a big job by any means.

I never thought they made a grout removal bit this narrow until started helping my son remodel an apartment building he recently purchased. The 1 inch square tile in the bathrooms had the narrowest of space between the tiles. When it came to regouting the Dremel 569 bit did the trick. I think the bit would be too narrow for using on regular 1/8" or larger grout.

Dremel makes a 1/8" thick bit. It's a lot sturdier and addresses the problem mentioned above.