Today found in old family junk Timson "UV desinfectors" for shoes.
These work from mains power.
Inside is MB6S (contrary to MB10S silkscreen) rectifier connected in series with a hugely heat-sinked resistor and it is powering 4 diodes.
I'm not sure these are real UV LEDs since they are bright blue. If they happen to be though (unlikely) would be nice to use them for pcb manufacturing and stuff.