What type of post processing are we talking?
Are we talking single items, or a multi number production type environment?
In general a high grit sand paper generally works for things like nylon.....but it depends on what type of surface finish he is looking to achieve.
We have a Form 2 SLA printer here at work and the material is ABS like. I usually use flush cutters to remove the supports and then use needle files to remove what I can as well as some fine grit sandpaper.