@AhLiGaddo I remember this problem hahaha! You can only start adding AP to HP or MP on a character starting at level 20! Calculate your expected MP at level 20. Then calculate minimum MP at level 20. The difference divided by 12 is how many HP washes you can do at level 20. You can do 5 HP washes at level 20. 5 HP washes at level 19. The later you save your AP for these HP washes, the more optimal it is since you’ll be using your AP now at level 11 to add into int.
My NL is 30K capable after I MP washed 350 times (70-140) with 350 base INT. (I only had like 320 base INT at 70, but I had 350 soon after that, so the difference is negligible.) I think this is nearly optimal. But you can always do more calculations now with @Shiyui 's calculator to find better approaches. I didn't have that luxury when I washed XD
Updated for lv 51~70 both of my mules were stuck at lv 66 for awhile because my ap resets ran out. I needed time to collect money for ap resets, glove and craven for my nl. I also needed to calculate optimal base int for my nl and mm for efficient mp washing. I've decided to base int at 340 for my nl and base int at 380 for my mm. .
Updated for 71~120 I am almost done collecting all ap resets I need for NL at lv 135. I've learned that mp gain from every ap is 11 + (base int *.1) +/-1 through experimenting on my mp washing. You lose static -12mp for your main stat. Overall average mp gain for every ap is (base int *.1) - 1.
For NL part: Updated for lv 121~135 back during February but I didn't finished. Finally finished from what I can remember and estimate. Updated for lv 136~174 to calculate how many ap resets I have used. For MM part: nothing interesting to add since I haven't used any ap reset after that 16 ap resets used at lv 50. P.S. thinking about making and hp washing a shadower next along with paladin maybe.