A saintly murder method

[ffutures]

I'm trying to identify one of Leslie Charteris' Saint stories in which Templar murders an abusive husband (I think in Italy) by poisoning him with the vapour from carbon tetrachloride dry cleaning fluid in a small sealed room - the murder method is suggested by a London doctor who says it's the perfect crime, but if anyone turns up killed that way he will have to report it to the police, unaware that Templar doesn't intend to use the method anywhere that he will hear about it.

Ring any bells with anyone?

Now identified Thanks to heliograph; The Cleaner Cure in Trust the Saint

Comments

[ffutures.livejournal.com]

Yes, that's the one - many thanks!