Hey, yes I have tried scrying with a mirror. It’s one of my favorite forms of divination too.
Water scrying and mirror scrying are inherently similar in terms of the fact that you’re both scrying into similar mediums, smooth, clear and reflective.
They differ in terms of the mediums individual properties. For example through mirror scrying I can get into the mirror realm, and that’s a whole entire experience on its own. Mirrors are more stable than water in terms of the fact that it can always remain frozen and perfectly still so you can always rely on it to scry.
With water there should be a certain quality to it to use it for proper scrying.
Another difference is that water inherently holds the energy of its element. That’s why i’m old folktales you would just need to stare at a lake or pond under a full moon to see visions.
This is because water holds those energies and powers within it, whether or not you choose to imbue it with a certain type of energy is your prerogative.
Mirrors however while they do act as great portals have to be consecrated with a certain energy in order to fully activate it for good scrying.
A lot of magicians who are skilled in scrying often consecrate their mirrors, either to a certain path of energy or to a deity who has ties to mirrors and their expert use ( Hathor and Lilith being good examples here )