Hi all, first time poster and DIY beginner.
Our showers are in need of a tidy up, and I am getting prepped to seal the grout, and removing then re-apply silicon. However I've noticed that our wall grout has cracks and imperfections, and our floor grout has some areas that dont appear fully filled.
I've been considering using a dunlop grout bottle to fill the gaps/top up the grout before sealing everything but I was looking to see if I'm on the right track?
Any suggestions would be appreciated.

