Anyone ever used grout pen?

[Imma]

We live in an old home (1940s) with a downstairs bathroom from the 1970s. It's still in working condition and we're not replacing it anytime soon, but it's currently super ugly. The wall tiles are a classic 1970s brown, but the problem is that the previous owner for some reason decided to paint the grout between the tiles bright green and burgundy. I'm not joking.

I've seen grout pen in shops, but as it's not cheap (€15 for one pen that covers 40 m, should be enough) I wonder if anyone has any experience with using it? It's available in several colours so you can match it to the colour of the tiles.

If it works, I think one afternoon of work will make our downstairs a million times more acceptable for the time being. That, and replacing the window frame - the previous owner put a plastic window frame that can't open into it... I know non-opening window frames are cheaper than windows you can actually open, but for a bathroom, really??

[gooki]

I've used it successfully to tidy up small areas of grout prior to selling our home. It like twink. I can't see a single pen doing 40 meters though. Maybe 10-20.

FWIW, I've also successfully painted tile edges (that's eposed to shower water), so a good paint, and a fine brush may also do the trick.

[CupcakeGuru]

I used to live in a 1940's apartment that had brown, pink and black tiles in the bathroom. Many people including me actually painted over the entire tiles, grout and all. They used kilz first to cover, then painted over with other colors. I did it in mine and it lasted over 10 years until the owners after me re-did the bathroom.

[Imma]

I painted a pink bathroom white in a previous apartment, and I've suggested that to my s/o too, but somehow he likes the awful tiles.....

[BlueHouse]

Yes, I used a grout pen and spent hours on my knees perfectly drawing the lines between tiles.  Then as I got more and more tired, I got sloppier and started getting paint on the tiles.  guess what?  It wipes right off the tiles.  So the next time I painted grout, I just slopped regular paint on with a paintbrush, then wiped the tiles off with a damp cloth.  After the paint dried, I did the same thing again with clear sealer -- you just have to wipe more often with the sealer because if that dries on the tile it's harder to get off.  This method held up very well for over 15 years in my only bathroom in my old house.