Vegetable matter can be removed chemically using sulphuric acid (carbonising).
The serial numbers have been chemically removed, but I'm betting that Goliath's gun was former Swiss military.
Most of the 'nasties' likely to get into your tank through the tap or from the fish and feeding them, can be removed chemically.
Remnants can be removed chemically, by use of oxygen scavenger.
Once the chip is assembled, the spacer layer is chemically removed and tiny piezoelectric actuators maintain the precise spacing required.
Where original trim remained, lead paint was chemically removed where necessary, and attempts were made to replicate missing historic trim.
Strong fibres were weakened by touching while weak fibres were improved in strength if the surface were removed chemically.
Shortly after, the process was improved; barium was removed chemically, by double precipitation from a solution as barium sulfate.
The silver images were chemically removed, leaving only the three layers of dye images in the finished film.
Lithium ions may be chemically removed by binding to species such as cryptands or crown ethers.