i'm trying to clean up the bathroom before we sell our house and have been cleaning the tiles. I've been able to clean them up pretty well but obviously after years of them being cleaned the grout between them has worn away a bit. I've called a few tilers but nobody wants the job of retiling them (understandable) because of potentially chipping the tiles and various other reasons. I was going to regrout them myself and went to b&q yesterday where they advised using unibond wall tile adhesive and grout over the top just to tidy them up? I've done a bit of research online and everywhere seems to say to take out the old grout first - can anyone help with this? I don't want to make a mess of the job but definitely need to get it tidied up!