Oil of cloves can be used as a replacement for the commercial treatments and it can be used to sedate, anaesthetise and euthanise when the dosage is altered appropriately.
The clove oil should be mixed with a little warm water first before adding it to the water and fish slowly.The most common method of drug administration is through immersion, a technique analogous to gaseous inhalant anesthesia in terrestrial animals, but the use of injectable anesthetic and sedative agents (primarily intramuscularly, but also intravenously) is increasing.Regardless of the route of administration, routine preprocedural preparation is appropriate, to stage both the animals and the supplies for induction, maintenance, and recovery.Aquarium fish can be safely and humanely euthanased by administering an overdose of anaesthetic dissolved in water.This method is especially appropriate for large fish that are difficult to handle but needs to be carried out by a veterinarian as the recommended anaesthetics (MS-222 Tricaine methanesulfonate and Benzocaine hydrochloride) are not available to the general public.For the hobbyist the only connection between these three treatments is Oil of cloves.
Commercial fish anaesthetics are only available to qualified vets and few others. Some compounds used for sedation only are available See Treatment finder.
But extrapolating from limited published anesthetic and sedative data to all fish species is potentially harmful because of marked anatomic, physiologic, and behavioral variations; instead, a stepwise approach to anesthetizing or sedating unfamiliar species or using unproven drugs for familiar species is advisable.
Additionally, knowledge of how water quality influences anesthesia or sedation helps limit complications.
It will be more stressful for the fish without sedation.
Place a heavy towel dampened with cold tap water as your base and then place another heavy cold tap water dampened towel over the fish covering the head but leaving the areas you're working on exposed.
Analgesia is an area in need of significant research as only a few studies exist and they provide some contrasting results.