I have had great success using distilled water for washing my porous, frizzy hiar, like a 70% improvement almost overnight.
Here in the UK it seems quite expensive, so can't really rely on this full time.
We already have a shower filter which has done nothing. Chelating shampoos and cider vinegar are ok but nowhere close to the wonders of distilled water.
What I want to know is can I use de-ionised water as a substitute? It is cheaper and available, but I can't find a reliable source for if it is safe. It is usually used for cleaning or feeding plants/steam irons, etc.
Hope someone has experience!