He's just trolling for a reaction, or he's a complete idiot. Either way he's best ignored.
All three
Going to the doctors & not answering questions for starters
Its like taking your motor to the garage & giving the mechanic half the story
Missing out the most important bits
& expecting the mechanic to work out what the problem is
IMO your bedside manner has been most accommodating
Maybe the bell-end patient needs a reminder as to what his obligations on UKP are
The listerine post by @southernbloke is bang on
A few klevva SPs have had a gargle after noshing me
& offered me the same given that i'd been doing some lapping
I usually take a small bottle with me, which you find in hotels
Replacing with full strength listerine