10int = 1mp extra for every class except mages.
144 int = 14 extra mp, or 3.5 hp resets per level.
edit - if a point in MP only gives you 2~4 mp, there is no point in double washing. you need to get more MP out of an AP point than the reset will take out. for ranged, double washing works because we get ~14mp per point in mp, and AP resets take out 12. if you only get 4, it won't work at all.
144 int = 14 extra mp, or 3.5 hp resets per level.
edit - if a point in MP only gives you 2~4 mp, there is no point in double washing. you need to get more MP out of an AP point than the reset will take out. for ranged, double washing works because we get ~14mp per point in mp, and AP resets take out 12. if you only get 4, it won't work at all.