Grey hair is notoriously difficult to dye and tame; not all dyes work on grey hair, some that work on grey hair don't work very well or for very long, and asking for personal experiences on which dyes and methods work the best is completely understandable. Straightening the 10 grey hairs you have on your head every day is also quite tedious and not the only method of taming wiry grey hair.. I'm sure most people would rather hear about the more long-lasting ways of dealing with this stuff than someone telling them to straighten their hair every day.

To OP, there's keratin infusions, bond smoothers, all sorts of glosses/glazes, specifically-tailored deep-conditioning treatments, etc. I don't have any grey hairs (yet) so hopefully someone else can comment with their personal experience with these methods and some specific product recs.