On my TS 125, getting the shoes re-lined with a softer lining and turned to match the hub helped. Possibly get the hub skimmed.
The usual thing is to fit a different brake, either the ETZ disc (Try the Sweller site – http://www.sweller.co.uk/mz/mods/mod_wab.html) or a honda twin leading shoe (You’ll need to lace a hub to the rim)
Alternatively buy good quality boots and put your feet down to stop (worked on my mopeds)