It doesn’t seem to be available here. Also worth mentioning is a Chlorhexidine wash. It’s known as Hibiclens in the states and Dexidin 2 in Canada. It’s available over the counter. I have several bottles saved up from a non elective surgery last fall. Was really paranoid about staph infections back then. A bit of irony now.
You will only do it once and won't gargle again with Chlorhexidine skin cleansers. ? They contain isopropyl alcohol AND surfactants (soap) . However, it is a great broad spectrum antimicrobial skin cleanser. I carry a small Hotel mouthwash bottle of Dexadin for washing my equipment after a session! I also use it to wash my armpits once a week or so to knock down any B.O. bacteria. There is a downside to using it as a body wash or labia/vagina area wash as a daily routine as it can throw off the normal flora and fauna that helps keep things balanced. Bacterial vaginosis and/or candida overgrowth (yeast infections) ca result.
Chlorhexidine oral rinses are available but I think they are Rx only now. Typically indicated for gingivitis.
Chlorhexidine has demonstrated efficacy against enveloped virus' like coronavirus. It also has an affinity for bonding to proteins like mucous membranes so it has some residual efficacy. However, it does have an affinity for staining teeth.
I have no idea how an oral rinse can be effective against Covid if it is inhaled . Gargling, done right, does not cause flushing of the airway or nasal passages.