For multiplication is that command OK, Or it's for adding two raster?
Con( IsNull( [Raster1] ), 0, [Raster1] ) + Con( IsNull( [Raster2] ), 0, [Raster2] )
For Multiply we should use the * (multiplication) Symbol as normal math, isn't it?
So the expression may be this one if I am not wrong.
'Con( IsNull( [Raster1] ), 0, [Raster1] ) * Con( IsNull( [Raster2] ), 0, [Raster2] )'
Regrads,
Najnin