Yes I have a 9mm Flobert gun - for those who do not know this 'Garden Gun' the shells are brass and look like .38 special wadcutter rounds, but they hold about 90 bb's.
And YES I have broken clays with them. At Stand 7 on Skeet they needed about 5 feet of lead

But they did break them. Hev never tried .22 snake shot.
While I lived in France, where they sell up to .45 in shotshell for "armes de defense" I saw people try to break clays, no-one succeeded.
These "armes de defense" look like the gun the imititate - say a .357 Colt Python, but they are smooth bore and have a bar down the centre of the barrel so they cannot fire a bullet, only bird shot. When I lived there you could carry these on your property only, but without a permit.
There now, a piece of shooting trivia for America's Birthday
Roger