Help with Late HP Washing (Lv61 Assassin)

Hey guys, I just started MapleLegends about a month or two now. I'm a level 61 Assassin, and I never knew anything about HP Washing until just now. when I hear that in order to basically do any of the Endgame content without getting destroyed, I should at least HP Wash a little bit. I really don't want to restart my character since i've invested so much time already, so I decided It'd probably be best to do some late washing and just boss with Hyper body.

I wanted to ask if anybody can help me make sure I'm planning everything right, and if anybody could help verify my calculations and explain a bit about the actual Washing process.

My Current Base Stats:

HP: 1795
MP:1073

I've tried following the guides for late washing here, and came up with this calculation:

Spoiler: Calculations

1073 Total MP No Equips
- 1002 Minimum MP At Lv 61
= 71 Additional MP

155 - (lv 61 + 10) = 84 Washing Levels

684 - 71 Add.MP = 613 Required MP

613 Required MP / 84 Washing Levels = 7 Int per level

Int Stat after all Equips: 47 INT

7 INT per level - 47 Total INT = 40 Additional Int

Please correct me if I'm wrong, but the way I interpret this is that I'm supposed to be putting all of my fresh level up AP into INT for 8 more levels until I have 40 base INT, on top of my 41 int from equips.

Do I save my fresh AP starting from level 69 all the way until 155 to invest in HP, and Swap out my MP and Base INT for my main stats with AP Resets?

If so, I'm assuming I need enough NX for a total of 124 AP resets?

Any help would be greatly appreciated, thank you!