What About sand blasting the plug?
I've been told no, don't do it, but I haven't had a problem. But I will also say that after blasting I look deep into the plug recess for any grit still trapped in there. Which is a good thing as I often find a few bits. Fortunately I am on friendly terms with a couple of dentists who have been kind enough to give me their surplus to requirement dental picks. So with those in hand I very carefully pick out the offending debris before it causes any problems. The picks also allow you to scrape the area of the central electrode that is shaded by the earth electrode.
The down side is the abrasive wears the glaze off of the ceramic and allows any fouling in the future a better grip. I used to work with a guy who swore that once a plug was fouled it was better to just trash it and get a new one. He wouldn't even wire brush them with a soft brass wire brush because he was of the opinion that even that destroyed the ceramic coating and made the plug useless. With that in mind I've tried cleaning fouled plugs with all sorts of solvents and blowing them out. I've tried solvents, wire brushes, and air. I've even tried burning off fouling with a propane torch. Nothing seems to work like blasting.
I've often wondered about oven cleaner. I sorting out a long running richness problem on my MG I've got a couple of fouled sets that are in need of a cleaning.
Once after blasting a set I also dropped them in my bench top ultra sonic cleaner with a strong mixture of simple green. Even after rinsing in fresh water and thoroughly drying with compressed air the metal developed that fuzzy white corrosion. After a quick going over with a brass wire brush, they still worked.
Spark plugs can take an amazing amount of abuse a still function.