co2 extraction wax and ice wax/ bubble hash is actually legal to sell in dispensaries.
I honestly don't know the legal status of CO2 extract hash in CA, but I'll take your word for it that this is legal, even though liquified CO2 is a solvent and a true CO2 based extract "should" be illegal under the exact same law that prohibits BHO.
If you mean dry ice hash, that's not a chemical solvent extraction, since the CO2 doesn't dissolve the trichrome heads, it just freezes them to make them run through a screen easier.
On water hash, that's simply not a solvent based product at all. Yes, water is a textbook polar solvent, but cannabinoids aren't soluble in water and it doesn't really apply here.
Instead water hash is made by mechanical (not chemical) extraction. As you know, its basically the same as dry sieved hash, only the trichrome heads are suspended in water to facilitate running them through nested screens.
water freezes into ice is a chemical change but that does not make it a chemical.
A chemical is any substance of distinct molecular composition that can't be reduced to others by mechanical separation.
So by the definition you'll find in chapter one of any chemistry textbook, water most certainly is a "chemical." So are nitrogen, oxygen, carbon dioxide, ethyl alcohol, butane, delta-9-THC, CBD, chlorophyll, and a million million others.
But without getting into semantic arguments here, again, water/bubble hash is made by mechanical, not chemical, extraction .